Method for transmitting and receiving system information in wireless communication system supporting tdd narrowband and apparatus therefor

ABSTRACT

This specification provides a method of receiving system information in a wireless communication system supporting a TDD narrowband. More specifically, the method performed by a user equipment includes receiving, from a base station, first system information on an anchor carrier, the first system information includes first information indicating whether a carrier used for second system information is an anchor carrier or a non-anchor carrier and second information on a location of the non-anchor carrier used for the second system information, and receiving, from the base station, the second system information on the non-anchor carrier based on the first system information. Accordingly, an SIB1-NB is transmitted and received even on a non-anchor carrier.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/KR2018/014022, filed on Nov. 15, 2018, which claims the benefit ofU.S. Provisional Application No. 62/635,448, filed on Feb. 26, 2018,U.S. Provisional Application No. 62/630,840, filed on Feb. 15, 2018,U.S. Provisional Application No. 62/591,142, filed on Nov. 27, 2017,U.S. Provisional Application No. 62/590,368, filed on Nov. 24, 2017,U.S. Provisional Application No. 62/586,186, filed on Nov. 15, 2017, thecontents of which are all hereby incorporated by reference herein intheir entirety.

TECHNICAL FIELD

This specification relates to a wireless communication system supportinga TDD narrowband and, more particularly, to a method for transmittingand receiving system information in a TDD NB-IoT system and an apparatustherefor.

BACKGROUND ART

Mobile communication systems have been generally developed to providevoice services while guaranteeing user mobility. Such mobilecommunication systems have gradually expanded their coverage from voiceservices through data services up to high-speed data services. However,as current mobile communication systems suffer resource shortages andusers demand even higher-speed services, development of more advancedmobile communication systems is needed.

The requirements of the next-generation mobile communication system mayinclude supporting huge data traffic, a remarkable increase in thetransfer rate of each user, the accommodation of a significantlyincreased number of connection devices, very low end-to-end latency, andhigh energy efficiency. To this end, various techniques, such as smallcell enhancement, dual connectivity, massive multiple input multipleoutput (MIMO), in-band full duplex, non-orthogonal multiple access(NOMA), supporting super-wide band, and device networking, have beenresearched.

DISCLOSURE Technical Problem

An object of this specification is to provide a method of transmittingand receiving system information on a non-anchor carrier in a TDD NB-IoTsystem.

Technical objects to be achieved in the present invention are notlimited to the above-described technical objects, and other technicalobjects not described above may be evidently understood by a personhaving ordinary skill in the art to which the present invention pertainsfrom the following description.

Technical Solution

This specification provides a method of receiving system information ina wireless communication system supporting a time division duplex (TDD)narrowband (NB).

More specifically, the method performed by a user equipment includesreceiving, from a base station, first system information on an anchorcarrier, wherein the first system information includes first informationindicating whether a carrier used for second system information is ananchor carrier or a non-anchor carrier and second information on alocation of the non-anchor carrier used for the second systeminformation, and receiving, from the base station, the second systeminformation on the non-anchor carrier based on the first systeminformation.

Furthermore, in this specification, the first system information is amasterinformationblock (MIB)-narrowband (NB), and the second systeminformation is a systeminformationblock1 (SIB1)-NB.

Furthermore, in this specification, the first information is configuredas the non-anchor carrier.

Furthermore, in this specification, the first system information furtherincludes operation mode information indicating an operation mode of thesystem. The location of the non-anchor carrier used for the secondsystem information is determined based on the operation mode.

Furthermore, in this specification, the location of the non-anchorcarrier is determined as a relative location with the anchor carrier.

Furthermore, in this specification, when the operation mode isconfigured as a guard band, the second control information indicates acarrier on the same side as the anchor carrier or a carrier on the sideopposite to the anchor carrier.

Furthermore, in this specification, if the operation mode is an in-bandor standalone, the second information indicates a frequency value lowerthan or higher than the anchor carrier.

Furthermore, in this specification, the relative location is representedas the interval of a physical resource block (PRB).

Furthermore, in this specification, the first system information furtherincludes third information indicating that the number of cell-specificreference signal (CRS) ports of the non-anchor carrier is identical withthe number of NRS ports of the anchor carrier or 4.

Furthermore, in this specification, the operation mode of the non-anchorcarrier is an in-band-different PCI.

Furthermore, in this specification, the second system information isreceived in a subframe #0 and a subframe #5.

Furthermore, in this specification, the repetition number of the secondsystem information on the non-anchor carrier is 8 or 16.

Furthermore, in this specification, the repetition number is determinedbased on a specific parameter included in the first system information.

Furthermore, in this specification, a narrowband reference signal (NRS)is received from the base station in the subframe #0 and the subframe#5.

Furthermore, this specification provides a user equipment receivingsystem information in a wireless communication system supporting a timedivision duplex (TDD) narrowband (NB), including a radio frequency (RF)module for transmitting and receiving radio signals and a processorcontrolling the RF module. The processor is configured to receive, froma base station, first system information on an anchor carrier, the firstsystem information includes first information indicating whether acarrier used for second system information is an anchor carrier or anon-anchor carrier and second information on a location of thenon-anchor carrier used for the second system information, and receive,from the base station, the second system information on the non-anchorcarrier based on the first system information.

Advantageous Effects

This specification has an effect in that system information can betransmitted and received on a non-anchor carrier by defining thelocation of system information on a non-anchor carrier and a relatedprocedure.

Effects which may be obtained in the present invention are not limitedto the above-described effects, and other technical effects notdescribed above may be evidently understood by a person having ordinaryskill in the art to which the present invention pertains from thefollowing description.

DESCRIPTION OF DRAWINGS

The accompanying drawings included as part of the detailed descriptionin order to help understanding of the present invention provideembodiments of the present invention, and describe the technicalcharacteristics of the present invention along with the detaileddescription.

FIG. 1 is a diagram showing an example of an LTE radio frame structure.

FIG. 2 is a diagram showing an example of a resource grid for a downlinkslot.

FIG. 3 shows an example of a downlink subframe structure.

FIG. 4 shows an example of an uplink subframe structure.

FIG. 5 shows an example of a frame structure type 1.

FIG. 6 is a diagram showing another example of a frame structure type 2.

FIG. 7 shows an example of a random access symbol group.

FIG. 8 is a diagram showing an example of a method for interpretingsignaling information of an SIB1-NB non-anchor carrier in a MIB-NB whenan anchor carrier proposed in this specification is a guard bandoperation mode.

FIG. 9 is a diagram showing another example of a method for interpretingsignaling information of an SIB1-NB non-anchor carrier in a MIB-NB whenan anchor carrier proposed in this specification is a guard bandoperation mode.

FIG. 10 is a diagram showing an example of the transmission location ofan SIB1-NB proposed in this specification.

FIGS. 11 and 12 show examples of the transmission location of an SIB1-NBaccording to a repetition number proposed in this specification.

FIG. 13 is a diagram showing an example of the codeword and resourcemapping of an SIB1-NB proposed in this specification.

FIG. 14 is a diagram showing an example of the location of a subframe inwhich an NPSS/NSSS/NPBCH/SIB1-NB is transmitted on an anchor-carrierproposed in this specification.

FIG. 15 is a diagram showing another example of the location of asubframe in which an NPSS/NSSS/NPBCH/SIB1-NB/NRS is transmitted on ananchor carrier proposed in this specification.

FIG. 16 is a flowchart showing an example of a user equipment operationfor performing a method proposed in this specification.

FIG. 17 is a flowchart showing an example of a base station operationfor performing a method proposed in this specification.

FIG. 18 illustrates a block diagram of a wireless communicationapparatus to which methods proposed in this specification may beapplied.

FIG. 19 is another example of a block diagram of a wirelesscommunication apparatus to which methods proposed in this specificationmay be applied.

MODE FOR INVENTION

Some embodiments of the present disclosure are described in detail withreference to the accompanying drawings. A detailed description to bedisclosed along with the accompanying drawings is intended to describesome exemplary embodiments of the present disclosure and is not intendedto describe a sole embodiment of the present disclosure. The followingdetailed description includes more details in order to provide fullunderstanding of the present disclosure. However, those skilled in theart will understand that the present disclosure may be implementedwithout such more details.

In some cases, in order to avoid making the concept of the presentdisclosure vague, known structures and devices are omitted or may beshown in a block diagram form based on the core functions of eachstructure and device.

In the present disclosure, a base station has the meaning of a terminalnode of a network over which the base station directly communicates witha terminal. In this document, a specific operation that is described tobe performed by a base station may be performed by an upper node of thebase station according to circumstances. That is, it is evident that ina network including a plurality of network nodes including a basestation, various operations performed for communication with a terminalmay be performed by the base station or other network nodes other thanthe base station. The base station (BS) may be substituted with anotherterm, such as a fixed station, a Node B, an eNB (evolved-NodeB), a basetransceiver system (BTS), or an access point (AP). Furthermore, theterminal may be fixed or may have mobility and may be substituted withanother term, such as user equipment (UE), a mobile station (MS), a userterminal (UT), a mobile subscriber station (MSS), a subscriber station(SS), an advanced mobile station (AMS), a wireless terminal (WT), amachine-type communication (MTC) device, a machine-to-Machine (M2M)device, or a device-to-device (D2D) device.

Hereinafter, downlink (DL) means communication from a base station toUE, and uplink (UL) means communication from UE to a base station. InDL, a transmitter may be part of a base station, and a receiver may bepart of UE. In UL, a transmitter may be part of UE, and a receiver maybe part of a base station.

Specific terms used in the following description have been provided tohelp understanding of the present disclosure, and the use of suchspecific terms may be changed in various forms without departing fromthe technical sprit of the present disclosure.

The following technologies may be used in a variety of wirelesscommunication systems, such as code division multiple access (CDMA),frequency division multiple access (FDMA), time division multiple access(TDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and non-orthogonalmultiple access (NOMA). CDMA may be implemented using a radiotechnology, such as universal terrestrial radio access (UTRA) orCDMA2000. TDMA may be implemented using a radio technology, such asglobal system for mobile communications (GSM)/general packet radioservice (GPRS)/enhanced data rates for GSM evolution (EDGE). OFDMA maybe implemented using a radio technology, such as Institute of electricaland electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX),IEEE 802.20, or evolved UTRA (E-UTRA). UTRA is part of a universalmobile telecommunications system (UMTS). 3rd generation partnershipproject (3GPP) Long term evolution (LTE) is part of an evolved UMTS(E-UMTS) using evolved UMTS terrestrial radio access (E-UTRA), and itadopts OFDMA in downlink and adopts SC-FDMA in uplink. LTE-advanced(LTE-A) is the evolution of 3GPP LTE.

Embodiments of the present disclosure may be supported by the standarddocuments disclosed in at least one of IEEE 802, 3GPP, and 3GPP2, thatis, radio access systems. That is, steps or portions that belong to theembodiments of the present disclosure and that are not described inorder to clearly expose the technical spirit of the present disclosuremay be supported by the documents. Furthermore, all terms disclosed inthis document may be described by the standard documents.

In order to more clarify a description, 3GPP LTE/LTE-A is chieflydescribed, but the technical characteristics of the present disclosureare not limited thereto.

General System

FIG. 1 is a diagram showing an example of an LTE radio frame structure.

In FIG. 1, the radio frame includes 10 subframes. The subframe includes2 slots in a time domain. Time for transmitting one subframe is definedas a transmission time interval (TTI). For example, one subframe mayhave a length of 1 millisecond (ms), and one slot may have a length of0.5 ms. One slot includes a plurality of orthogonal frequency divisionmultiplexing (OFDM) symbols in the time domain. An OFDM symbol is forrepresenting one symbol period because 3GPP LTE uses OFDMA in downlink.The OFDM symbol may be referred to as an SC-FDMA symbol or a symbolperiod. A resource block (RB) is a resource allocation unit and aplurality of contiguous subcarriers in one slot. The structure of theradio frame is illustrative. Accordingly, the number of subframesincluded in the radio frame, the number of slots included in a subframe,or the number of OFDM symbols included in a slot may be modified invarious manners.

FIG. 2 is a diagram showing an example of a resource grid for a downlinkslot.

In FIG. 2, the downlink slot includes a plurality of OFDM symbols in atime domain. In this specification, for example, one downlink slot isillustrated as including 7 OFDM symbols and one resource block (RB) isillustrated as including 12 subcarriers in a frequency domain. However,the present invention is not limited to the above examples. Each elementof the resource grid is referred to as a resource element (RE). One RBincludes 12×7 REs. The number NDL of RBs included in the downlink slotis different depending on a downlink transmission bandwidth. Thestructure of an uplink slot may be the same as that of a downlink slot.

FIG. 3 shows an example of a downlink subframe structure.

In FIG. 3, a maximum of 3 OFDM symbols positioned in the front part ofthe first slot within a subframe is a control area to which a controlchannel is allocated. The remaining OFDM symbols correspond to a dataarea to which a PDSCH is allocated. Examples of downlink controlchannels used in I3GPP LTE include a physical control format indicatorchannel (PCFICH), a physical downlink control channel (PDCCH), aphysical hybrid ARQ indicator channel (PHICH), etc. The PCFICH istransmitted in the first OFDM symbol of a subframe, and carriesinformation on OFDM symbols used for the transmission of controlchannels within a subframe. The PHICH is a response to uplinktransmission and carries a HARQ acknowledgment(ACK)/negative-acknowledgment (NACK) signal. Control informationtransmitted through a PDCCH is referred to as downlink controlinformation (DCI). DCI includes uplink or downlink schedulinginformation or includes an uplink transmission (Tx) power controlcommand for given UE groups.

A PDCCH may carry the transport format and resource allocation of adownlink shared channel (DL-SCH), resource allocation information of anuplink shared channel (UL-SCH), paging information on a paging channel(PCH), system information on a DL-SCH, resource allocation of a higherlayer control message such as a random access response transmitted on aPDSCH, a set of Tx power control commands for UEs within an arbitrary UEgroup, the Tx power control command of a voice over IP (VoIP),activation, etc. A plurality of PDCCHs may be transmitted within thecontrol area. A UE may monitor a plurality of PDCCHs. A PDCCH istransmitted on an aggregation of one or some contiguous control channelelements (CCEs). A CCE is a logical allocation unit used to provide aPDCCH with a coding rate based on the state of a radio channel. A CCEcorresponds to a plurality of resource element groups. The format of aPDCCH and the number of available bits of the PDCCH is determined basedon the correlation between the number of CCEs and a coding rate providedby the CCEs. A BS determines a PDCCH format based on DCI that needs tobe transmitted to a UE, and attaches a cyclic redundancy check (CRC) tocontrol information. The CRC is masked with a unique identifier (calledradio network temporary identifier (RNTI)) depending on the owner or useof a PDCCH. If a PDCCH is for a specific UE, a CRC may be masked with aunique identifier (e.g., cell-RNTI (C-RNTI)) of the specific UE. Foranother example, if a PDCCH is for a paging message, a CRC may be maskedwith a paging indicator identifier (e.g., paging-RNTI (P-RNTI)). If aPDCCH is for system information (system information block (SIB) to bedescribed more specifically), a CRC may be masked with a systeminformation identifier and a system information RNTI (SI-RNTI). A CRCmay be masked with a random access-RNTI (RA-RNTI) in order to indicate arandom access response, that is, a response to the transmission of arandom access preamble by a UE.

FIG. 4 shows an example of an uplink subframe structure.

In FIG. 4, the uplink subframe may be divided into a control area and adata area in a frequency domain. A physical uplink control channel(PUCCH) for carrying uplink control information is allocated to thecontrol area. A physical uplink shared channel (PUSCH) for carrying userdata is allocated to the data area. In order to maintain a singlecarrier characteristic, one UE does not transmit a PUCCH and a PUSCH atthe same time. A PUCCH for one UE is allocated to an RB pair within asubframe. An RB belonging to an RB pair occupies different subcarriersin two slots. This is called that an RB pair allocated to a PUCCH isfrequency-hopped at a slot boundary.

Hereinafter, an LTE frame structure is described more specifically.

The sizes of various fields in the time domain is represented as thenumber of time units of T_(s)=1/(15000×2048) seconds unless describedotherwise through the LTE specification.

Downlink and uplink transmissions are organized as a radio frame havingduration of T_(f)=307200×T_(s)=10m. Two radio frame structures aresupported.

-   -   Type 1: applicable to FDD    -   Type 2: applicable to TDD

Frame Structure Type 1

The frame structure type 1 may be applied to both full duplex and halfduplex FDD. Each radio frame is T_(f)=307200 T=10 ms length, and isconfigured with slots, that is, T_(f)=307200·T_(s)=10 ms. The slots arenumbered from 0 to 19. A subframe is defined as two contiguous slots,and a subframe i includes slots 2i and 2i+1.

In the case of FDD, 10 subframes are available for downlinktransmission, and subframes are available for uplink transmission every10 ms interval.

Uplink and downlink transmissions are separated in the frequency domain.In a half duplex FDD operation, a UE cannot transmit and receive data atthe same time, but there is no limit in full duplex FDD.

FIG. 5 shows an example of a frame structure type 1.

Frame Structure Type 2

The frame structure type 2 may be applied to FDD. The length of eachradio frame of a length T_(f)=307200×T_(s)=10 ms includes twohalf-frames, each one having 15360·T_(s)=0.5 ms. Each half-frameincludes 5 subframes of length 30720·T_(s)=1 ms. Supporteduplink-downlink configurations are listed in Table 2. In this case, ineach subframe within a radio frame, “D” indicates that a subframe hasbeen reserved for downlink transmission, “U” indicates that a subframehas been reserved for uplink transmission, and “S” indicates a specialsubframe having three fields of a downlink pilot time slot (DwPTS), aguard period (GP) and an uplink pilot time slot (UpPTS). On the premisethat a DwPTS, GP and UpPTS have a total length 30720·T_(s)=1 ms, thelength of the DwPTS and UpPTS is provided by Table 1. In each subframei, a length within each subframe is defined as two slots 2i and 2i+1,that is, T_(slot)=15360·T_(s)=0.5 m.

An uplink-downlink configuration having switch-point periodicity fromdownlink to uplink in both 5 ms and 10 ms is supported. In the case ofswitch-point periodicity from downlink to uplink of 5 ms, a specialsubframe is present in both two half-frames. In the case of switch-pointperiodicity from downlink to uplink of 10 ms, the special subframe ispresent only in the first half-frame. Subframes 0 and 5 and a DwPTS arealways reserved for downlink transmission. An UpPTS and a subframesubsequent to the special subframe are always reserved for uplinktransmission.

FIG. 6 is a diagram showing another example of a frame structure type 2.

Table 1 shows an example of the configuration of a special subframe.

TABLE 1 Normal cyclic prefix in downlink Extended cyclic prefix indownlink UpPTS UpPTS Special Normal Extended Normal Extended subframecyclic prefix cyclic prefix cyclic prefix cyclic prefix configurationDwPTS in uplink in uplink DwPTS in uplink in uplink 0  6592 · T_(s) 2192· T_(s) 2560 · T_(s)  7680 · T_(s) 2192 · T_(s) 2560 · T_(s) 1 19760 ·T_(s) 20480 · T_(s) 2 21952 · T_(s) 23040 · T_(s) 3 24144 · T_(s) 25600· T_(s) 4 26336 · T_(s)  7680 · T_(s) 4384 · T_(s) 5120 · T_(s) 5  6592· T_(s) 4384 · T_(s) 5120 · T_(s) 20480 · T_(s) 6 19760 · T_(s) 23040 ·T_(s) 7 21952 · T_(s) — — — 8 24144 · T_(s) — — —

Table 2 shows an example of an uplink-downlink configuration.

TABLE 2 Uplink- Downlink- Downlink to-Uplink config- Switch-pointSubframe number uration periodicity 0 1 2 3 4 5 6 7 8 9 0 5 ms D S U U UD S U U U 1 5 ms D S U U D D S U U D 2 5 ms D S U D D D S U D D 3 10 msD S U U U D D D D D 4 10 ms D S U U D D D D D D 5 10 ms D S U D D D D DD D 6 5 ms D S U U U D S U U D

NB-IoT

A narrowband-Internet of things (NB-IoT) is a standard for supportinglow complexity, low cost devices, and has been defined to perform only arelatively simple operation compared to the existing LTE devices. TheNB-IoT follows the basic structure of LTE, but operates based on thefollowing defined contents. If the NB-IoT reuses a channel or signal ofLTE, it may follow the standard defined in the existing LTE.

Uplink

The following narrowband physical channels are defined.

-   -   Narrowband physical uplink shared channel (NPUSCH)    -   Narrowband physical random access channel (NPRACH)    -   The following uplink narrowband physical signals are defined.    -   Narrowband demodulation reference signal

In a subcarrier N_(sc) ^(UL) aspect, an uplink bandwidth and slotduration T_(slot) are given in Table 3.

Table 3 shows an example of NB-IoT parameters.

TABLE 3 Subcarrier Spacing N_(sc) ^(UL) T_(slot) Δf = 3.75 kHz 48 61440· T_(s) Δf = 15 kHz 12 15360 · T_(s)

A single antenna port p=0 is used for all uplink transmissions.

Resource Unit

A resource unit is used to describe the mapping of an NPUSCH and aresource element. The resource unit is defined as contiguous symbols ofN_(symb) ^(UL)N_(slots) ^(UL) in the time domain, and is defined ascontiguous subcarriers of N_(sc) ^(RU) in the frequency domain. In thiscase, N_(sc) ^(RU) and N_(symb) ^(UL) are given in Table 4.

Table 4 shows an example of supported combinations of N_(sc) ^(RU),N_(slots) ^(UL) and N_(symb) ^(UL).

TABLE 4 NPUSCH format Δf N_(sc) ^(RU) N_(slots) ^(UL) N_(symb) ^(UL) 13.75 kHz 1 16 7   15 kHz 1 16 3 8 6 4 12 2 2 3.75 kHz 1 4   15 kHz 1 4

Narrowband Uplink Shared Channel (NPUSCH)

A narrowband physical uplink shared channel is supported by two formats:

-   -   NPUSCH format 1 used to carry an UL-SCH    -   NPUSCH format 2 used to carry uplink control information

Scrambling is performed according to Paragraph 5.3.1 of TS36.211. Ascrambling sequence generator is initialized asc_(ini)=n_(RNTI)·2¹⁴+n_(f) mod 2·2¹³+└n_(s)/2┘+N_(ID) ^(cell). In thiscase, n_(s) is the first slot of codeword transmission. In the case ofNPUSCH repetition, a scrambling sequence is re-initialized as n_(s) andn_(f) configured as the first slot and a frame, respectively, used forrepetition transmission after all M_(identical) ^(NPUSCH) codewordtransmission according to the above equation. Quantity M_(identical)^(NPUSCH) is provided by Paragraph 10.1.3.6 of TS36.211.

Table 5 specifies modulation mappings applicable to narrowband physicaluplink shared channel.

TABLE 5 NPUSCH format N_(SC) ^(RU) Modulation method 1 1 BPSK, QPSK >1QPSK 2 1 BPSK

An NPUSCH may be mapped to one or more resource units N_(RU), such asthat provided by Paragraph 3GPP TS 36.213. The one or more resourceunits are transmitted M_(rep) ^(NPUSCH) times.

In order to follow transmit power P_(NPUSCH) defined in 3GPP TS 36.213,the block z(0), . . . , z(M_(rep) ^(NPUSCH)−1) of complex-value symbolsis multiplied by a size scaling element β_(NPUSCH), and is mapped tosubcarriers allocated for the transmission of an NPUSCH as a sequencethat starts from z(0). Mapping to a resource element (k,l) allocated fortransmission and corresponding to subcarriers not used for thetransmission of reference signals becomes an increment sequence of anindex k, a subsequent index l starting from the first slot of anallocated resource unit.

Prior to continuous mapping to the following slot of z(⋅) afterN_(slots) slot mapping, N_(slot)s slots are repeated as an M_(identical)^(NPUSCH)−1 additional number. In this case, Equation 1 is as follows:

$\begin{matrix}{M_{idendical}^{NPUSCH} = \{ {{\begin{matrix}{{in}( {\lceil {M_{rep}^{NPUSCH}/2} \rceil,4} )} & {N_{sc}^{RU} > 1} \\1 & {N_{sc}^{RU} = 1}\end{matrix}N_{slots}} = \{ \begin{matrix}1 & {{\Delta \; f} = {3.75\mspace{14mu} {kHz}}} \\2 & {{\Delta \; f} = {15\mspace{14mu} {kHz}}}\end{matrix} } } & \lbrack {{Equation}\mspace{14mu} 1} \rbrack\end{matrix}$

If mapping to an N_(slots) slot or the repetition of the mappingincludes a resource element overlapping a given configured NPRACHresource according to NPRACH-ConfigSIB-NB, the NPUSCH transmission ofthe overlapped N_(slots) slots is postponed until next N_(slots) slotsdo not overlap a given configured NPRACH resource.

Mapping of z(0), . . . , z(M_(rep) ^(NPUSCH)−1) is repeated untilM_(rep) ^(NPUSCH)N_(RU)N_(slots) ^(UL) slots are transmitted. Aftertransmissions and/or postponements by an NPRACH of a 256·30720T_(s) timeunit, if NPUSCH transmission is postponed, the gap of a 40·30720T_(s)time unit is inserted. The postponement part attributable to an NPRACHmatched with the gap is counted as part of the gap.

If a higher layer parameter npusch-AllSymbols is configured to be false,the resource elements of an SC-FDMA symbol overlapping a symbolconfigured as an SRS according to srs-SubframeConfig is calculated asNPUSCH mapping, but is not used for the transmission of an NPUSCH. Ifthe higher layer parameter npusch-AllSymbols is configured to be true,all symbols are transmitted.

Uplink control information on an NPUSCH without UL-SCH data

1 bit information of HARQ-ACK o₀ ^(ACK) is coded according to Table 6.In this case, o₀ ^(ACK)=1 with respect to ACK, and o₀ ^(ACK)=0 withrespect to NACK.

Table 6 shows an example of HARQ-ACK codewords.

TABLE 6 HARQ-ACK HARQ-ACK <o₀ ^(ACK>) <b₀, b₁, b₂, . . . , b₁₅> 0 <0, 0,0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0> 1 <1, 1, 1, 1, 1, 1, 1, 1, 1,1, 1, 1, 1, 1, 1, 1>

Power Control

In an NB-IoT UL slot i for a serving cell, UE transmit power for NPUSCHtransmission is provided like Equations 2 and 3.

When the repetition number of allocated NPUSCH RUs is greater than 2,

P _(NPUSCH,c)(i)=P _(CMAX,c)(i) [dBm]  [Equation 2]

Otherwise,

                                     [Equation  3]${P_{{NPUSCH},c}(i)} = {\min {\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\{{10\; {\log_{10}( {M_{{NPUSCH},c}(i)} )}} + {P_{{O\_ NPUSCH},c}(j)} + {{\alpha_{c}(j)} \cdot {PL}_{c}}}\end{Bmatrix}\mspace{11mu}\lbrack{dBm}\rbrack}}$

In this case, P_(CMAX,c)(i) is configured UE transmit power defined in3GPP TS36.101 in an NB-IoT UL slot i with respect to a serving cell c.

M_(NPUSCH,c) is {¼} with respect to 3.75 kHz subcarrier spacing, and is{1,3,6,12} with respect to 15 kHz subcarrier spacing.

P_(O_NPUSCH,c)(j) has the sum of a component P_(O_NOMINAL_NPUSCH,c)(j)provided by higher layers with respect to the serving cell c and acomponent P_(O_UE_NPUSCH,c)(j) provided by higher layers with respect toj=1. In this case, j e {1, 2}. j=1 with respect to NPUSCH(re)transmissions corresponding to a dynamic-scheduled grant, and j=2with respect to NPUSCH (re)transmissions corresponding to a randomaccess response grant.

P_(O_UE_NPUSCH,c)(2)=0 andP_(O_NORMINAL_NPUSCH,c)(2)=P_(O_PRE)+Δ_(PREAMBLE_Msg3). In this case,parameters preambleInitialReceivedTargetPower P_(O_PRE) andΔ_(PREAMBLE_Msg3) are signaled from higher layers with respect to theserving cell c.

With respect to j=1, α_(c)(j)=1 is provided by higher layers withrespect to the NPUSCH format 2; α_(c)(j) is provided by higher layerswith respect to the NPUSCH format 1 with respect to the serving cell c.α_(c)(j)=1 with respect to j=2.

PL_(c) is downlink pathloss estimation calculated in dB by a UE withrespect to the serving cell c, andPL_(c)=nrs-Power+nrs-PowerOffsetNonAnchor−higher layer-filtered NRSRP.In this case, nrs-Power is provided by higher layers and lower Paragraph16.2.2 of 3GPP 36.213. If nrs-powerOffsetNonAnchor is not provided byhigher layers, it is set to zero. NRSRP is defined in 3GPP TS 36.214with respect to the serving cell c, and a higher layer filterconfiguration is defined in 3GPP TS 36.331 with respect to the servingcell c.

When a UE transmits an NPUSCH in an NB-IoT UL slot i with respect to theserving cell c, a power headroom is calculated using Equation 4.

PH _(c)(i)=P _(CMAX,c)(i)−{P _(O_NPUSCH,c)(1)+α_(c)(1)·PL _(c)}[dB]  [Equation 4]

UE Procedure for Transmitting Format 1 NPUSCH

When an NPDCCH having the DCI format N0 ended in an NB-IoT DL subframe nfor a UE is detected in a given serving cell, the UE performscorresponding NPUSCH transmission using the NPUSCH format 1 in Ncontiguous NB-IoT UL slots n_(i), that is, i=0, 1, . . . , N−1, based onNPDCCH information at the end of an n+k₀ DL subframe. In this case,

The subframe n is the last subframe in which the NPDCCH is transmitted,and is determined by the start subframe of the NPDCCH transmission andthe DCI subframe repetition number field of corresponding DCI.Furthermore,

N=N_(Rep)N_(RU)N_(slots) ^(UL). In this case, the value of N_(Rep) isdetermined by the repetition number field of the corresponding DCI. Thevalue of N_(RU) is determined by the resource allocation field of thecorresponding DCI. The value of N_(slots) ^(UL) is the number of NB-IoTUL slots of a resource unit corresponding to the number of subcarriersallocated in the corresponding DCI.

n₀ is the first NB-IoT UL slot that starts after the end of the subframen+k₀.

The value of k₀ is determined by the scheduling delay field (I_(Delay))of the corresponding DCI according to Table 7.

Table 7 shows an example of k0 for the DCI format N0.

TABLE 7 I_(Delay) k₀ 0 8 1 16 2 32 3 64

Resource allocation information of an uplink DCI format N0 for NPUSCHtransmission is indicated by a scheduled UE.

-   -   Set of contiguously allocated subcarriers (n_(sc)) of a resource        unit determined by the subcarrier indication field of        corresponding DCI    -   Multiple resource units (N_(RU)) determined by the resource        allocation field of corresponding DCI according to Table 9    -   Repetition number (N_(Rep)) determined by the repetition number        field of corresponding DCI according to Table 10

The subcarrier spacing Δf of NPUSCH transmission is determined by theuplink subcarrier spacing field of a narrowband random access responsegrant according to Lower Paragraph 16.3.3 of 3GPP TS36.213.

In the case of NPUSCH transmission having subcarrier spacing Δf=3.75kHz, n_(sc)=I_(sc). In this case, I_(sc) is the subcarrier indicationfield of DCI.

In the case of NPUSCH transmission having subcarrier spacing Δf=15 kHz,the subcarrier indication field (I_(sc)) of DCI determines a set ofcontiguously allocated subcarriers (n_(sc)) according to Table 8.

Table 8 shows an example of subcarriers allocated to an NPUSCH havingΔf=15 kHz.

TABLE 8 Subcarrier indication field (I_(sc)) Set of allocatedsubcarriers (n_(sc))  0-11 I_(sc) 12-15 3(I_(sc)-12) + {0,1,2} 16-176(I_(sc)-16) + {0,1,2,3,4,5} 18 {0,1,2,3,4,5,6,7,8,9,10,11} 19-63Reserved

Table 9 shows an example of the number of resource units for an NPUSCH.

TABLE 9 I_(RU) N_(Ru) 0 1 1 2 2 3 3 4 4 5 5 6 6 8 7 10

Table 10 shows an example of the repetition number of an NPUSCH.

TABLE 10 I_(Rep) N_(Rep) 0 1 1 2 2 4 3 8 4 16 5 32 6 64 7 128

Demodulation Reference Signal (DMRS)

A reference signal sequence r _(u)(n) for N_(sc) ^(RU)=1 is defined byEquation 5.

$\begin{matrix}{{{{\overset{\_}{r}}_{u}(n)} = {\frac{1}{\sqrt{2}}( {1 + j} )( {1 - {2{c(n)}}} ){w( {n\mspace{14mu} {mod}\mspace{14mu} 16} )}}},{0 \leq n < {M_{rep}^{NPUSCH}N_{RU}N_{slots}^{UL}}}} & \lbrack {{Equation}\mspace{14mu} 5} \rbrack\end{matrix}$

In this case, the binary sequence c(n) is defined by 7.2 of TS36.211,and needs to be initialized as c_(init)=35 when NPUSCH transmissionstarts. The value w(n) is provided by Table 1-11. In this case, whengroup hopping is not enabled with respect to the NPUSCH format 1,u=N_(ID) ^(cell) mod 16 for the NPUSCH format 2. When group hopping isenabled with respect to the NPUSCH format 1, the value w(n) is providedby Paragraph 10.1.4.1.3 of 3GPP TS36.211.

Table 11 shows an example of w(n).

TABLE 11 u w(0), . . . , w(15) 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 −11 −1 1 −1 1 −1 1 −1 1 −1 1 −1 1 −1 2 1 1 −1 −1 1 1 −1 −1 1 1 −1 −1 1 1−1 −1 3 1 −1 −1 1 1 −1 −1 1 1 −1 −1 1 1 −1 −1 1 4 1 1 1 1 −1 −1 −1 −1 11 1 1 −1 −1 −1 −1 5 1 −1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 −1 1 6 1 1 −1 −1−1 −1 1 1 1 1 −1 −1 −1 −1 1 1 7 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −18 1 1 1 1 1 1 1 1 −1 −1 −1 −1 −1 −1 −1 −1 9 1 −1 1 −1 1 −1 1 −1 −1 1 −11 −1 1 −1 1 10 1 1 −1 −1 1 1 −1 −1 −1 −1 1 1 −1 −1 1 1 11 1 −1 −1 1 1 −1−1 1 −1 1 1 −1 −1 1 1 −1 12 1 1 1 1 −1 −1 −1 −1 −1 −1 −1 −1 1 1 1 1 13 1−1 1 −1 −1 1 −1 1 −1 1 −1 1 1 −1 1 −1 14 1 1 −1 −1 −1 −1 1 1 −1 −1 1 1 11 −1 −1 15 1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1

A reference signal sequence for the NPUSCH format 1 is provided byEquation 6.

r _(u)(n)= r _(u)(n)  [Equation 6]

A reference signal sequence for the NPUSCH format 2 is provided byEquation 7.

r _(u)(3n+m)= w (m) r _(u)(n), m=0,1,2  [Equation 7]

In this case, w(m) is defined as Table 5.5.2.2.1-2 of 3GPP TS36.211having a sequence index selected based on

$( {\sum\limits_{i = 0}^{7}{{c( {{8n_{s}} + i} )}2^{i}}} ){mod3}$

with c_(init)=N_(ID) ^(cell).

A reference signal sequences r_(u)(n) for N_(sc) ^(RU)>1 is defined bythe cyclic shift α of a base sequence according to Equation 8.

r _(u)(n)=e ^(jαn) e ^(jϕ(n)π/4), 0≤n<N _(sc) ^(RU)  [Equation 8]

In this case, φ(n) is provided by Table 10.1.4.1.2-1 with respect toN_(sc) ^(RU)=3, is provided by Table 12 with respect to N_(sc) ^(RU)=6,and is provided by Table 13 with respect to N_(sc) ^(RU)=12.

When group hopping is not enabled, a base sequence index u is providedby higher layer parameters threeTone-BaseSequence, sixTone-BaseSequence,and twelveTone-BaseSequence, respectively, with respect to N_(sc)^(RU)=3, N_(sc) ^(RU)=6, and N_(sc) ^(RU)=12. When group hopping is notsignaled by higher layers, a base sequence is provided by Equation 9.

$\begin{matrix}{u = \{ \begin{matrix}{N_{ID}^{Ncell}{mod12}} & {{{for}\mspace{14mu} N_{sc}^{RU}} = 3} \\{N_{ID}^{Ncell}{mod14}} & {{{for}\mspace{14mu} N_{sc}^{RU}} = 6} \\{N_{ID}^{N\; {cell}}{mod30}} & {{{for}\mspace{14mu} N_{sc}^{RU}} = 12}\end{matrix} } & \lbrack {{Equation}\mspace{14mu} 9} \rbrack\end{matrix}$

When group hopping is enabled, the base index u is provided by Paragraph10.1.4.1.3 of 3GPP TS36.211.

A cyclic shift for N_(sc) ^(RU)=3 and N_(sc) ^(RU)=6, as defined inTable 14, are derived from respective higher layer parametersthreeTone-CyclicShift and sixTone-CyclicShift. α=0 for N_(sc) ^(RU)=12.

Table 12 is a table showing an example of φ(n) for N_(sc) ^(RU)=3.

TABLE 12 u φ(0), φ(1), φ(2) 0 1 −3 −3 1 1 −3 −1 2 1 −3 3 3 1 −1 −1 4 1−1 1 5 1 −1 3 6 1 1 −3 7 1 1 −1 8 1 1 3 9 1 3 −1 10 1 3 1 11 1 3 3

Table 13 is a table showing another example of φ(n) for N_(sc) ^(RU)=6.

TABLE 13 u φ(0), . . . , φ(5) 0 1 1 1 1 3 −3 1 1 1 3 1 −3 3 2 1 −1 −1 −11 −3 3 1 −1 3 −3 −1 −1 4 1 3 1 −1 −1 3 5 1 −3 −3 1 3 1 6 −1 −1 1 −3 −3−1 7 −1 −1 −1 3 −3 −1 8 3 −1 1 −3 −3 3 9 3 −1 3 −3 −1 1 10 3 −3 3 −1 3 311 −3 1 3 1 −3 −1 12 −3 1 −3 3 −3 −1 13 −3 3 −3 1 1 −3

Table 14 is a table showing an example of a.

TABLE 14 N_(sc) ^(RU) = 3 N_(sc) ^(RU) = 6 3 tone-cyclic shift 6tone-cyclic shift (threeTone-CyclicShift) α (sixTone-CyclicShift) α 0 00 0 1 2π/3 1 2π/6 2 4π/3 2 4π/6 3 8π/6

For a reference signal for the NPUSCH format 1, sequence-group hoppingmay be enabled. In this case, the sequence-group number u of the slotn_(s) is defined by a group hopping pattern f_(gh)(n_(s)) and asequence-shift pattern f_(ss) according to Equation 10.

u=(f _(gh)(n _(s))+f _(ss))mod N _(seq) ^(RU)  [Equation 10]

In this case, the number of reference signal sequences, N_(s) uavailable for each resource unit size is provided by Table 15.

Table 15 shows an example of N_(seq) ^(RU).

TABLE 15 N_(sc) ^(RU) N_(seq) ^(RU) 1 16 3 12 6 14 12 30

Sequence-group hopping is enabled or disabled by cell-specificparameters groupHoppingEnabled provided by higher layers. Sequence grouphopping for an NPUSCH may be disabled by a specific UE through ahigher-layer parameter groupHoppingDisabled unless NPUSCH transmissioncorresponds to the retransmission of the same transport block or arandom access response grant as part of a contention-based random accessprocedure.

A group hopping pattern f_(gh)(n_(s)) is provided by Equation 11.

f _(gh)(n _(s))=(Σ_(i=0) ⁷ c(8n _(s) ′+i)·2^(i))mod N _(seq)^(RU)  [Equation 11]

In this case, n_(s)′=n_(s) for N_(sc) ^(RU)>1, and n_(s)′ is the slotnumber of the first slot of a resource unit. The pseudo-random sequencec(i) is defined by Paragraph 7.2. The pseudo-random sequence generatoris initialized as

$c_{init} = \lfloor \frac{N_{ID}^{Ncell}}{N_{seq}^{RU}} \rfloor$

at the start of a resource unit with respect to N_(sc) ^(RU)=1 and ineach even-numbered slot with respect to N_(sc) ^(RU)>1

A sequence-shift pattern f_(ss) is provided by Equation 12.

f _(ss)=(N _(ID) ^(Ncell)+Δ_(ss))mod N _(seq) ^(RU)  [Equation 12]

In this case, Δ_(ss)∈{0, 1, . . . , 29} is provided by a higher-layerparameter groupAssignmentNPUSCH. If the value is not signaled, Δ_(ss)=0.

A sequence r(⋅) needs to be multiplied by a size scaling factorβ_(NPUSCH) and needs to be mapped to subcarriers as a sequence thatstarts as r(0).

A set of subcarriers used for a mapping process needs to be the same ascorresponding NPUSCH transmission defined in Paragraph 10.1.3.6 of 3GPP36.211.

In mapping to resource elements (k,l), an increment sequence of the slotnumber needs to be the first k, subsequently l, and the last. The valuesof the symbol index l within the slot are provided in Table 16.

Table 16 shows an example of demodulation reference signal locations foran NPUSCH.

TABLE 16 Values for l NPUSCH format Δf = 3.75 kHz Δf = 15 kHz 1 4 3 20,1,2 2,3,4

SF-FDMA Baseband Signal Generation

With respect to N_(sc) ^(RU)>1, the time-contiguous signal s_(l)(t) ofan SC-FDMA symbol l within a slot is defined by Paragraph 5.6 as a valueN_(RB) ^(UL)N_(sc) ^(RB) substituted with N_(sc) ^(UL).

With respect to N_(sc) ^(RU)=1 the time-contiguous signal s_(k,l)(t) forthe subcarrier index k of an SC-FDMA symbol l within an uplink slot isdefined by Equation 13.

s _(k,l)(t)α_(k) ⁽⁻⁾ _(,l) ·e ^(jϕ) ^(k,l) ·e ^(j2π(k+1/2)Δf(t−N)^(CP,l) ^(T) ^(s) ⁾

k ⁽⁻⁾ =k+└N _(sc) ^(UL)/2┘  [Equation 13]

0≤t≤(N_(CP,l)+N)T_(s). In this case, parameters for Δf=15 kHz andΔf=3.75 kHz are provided by Table 17. a_(k) ⁽⁻⁾ _(,l) is the modulationvalue of the symbol l, and phase rotation φ_(k,l) is defined by Equation14.

$\begin{matrix}{\mspace{79mu} {{\phi_{k,l} = {{\rho ( {\overset{\sim}{l}\mspace{14mu} {mod}\mspace{14mu} 2} )} + {{\hat{\phi}}_{k}( \overset{\sim}{l} )}}}\mspace{79mu} {\rho = \{ {{\begin{matrix}{\frac{\pi}{2}\mspace{14mu} {for}\mspace{14mu} {BPSK}} \\{\frac{\pi}{4}\mspace{14mu} {for}\mspace{14mu} {QPSK}}\end{matrix}{{\hat{\phi}}_{k}( \overset{\sim}{l} )}} = \{ {{{\begin{matrix}0 & {\overset{\sim}{l} = 0} \\{{{\hat{\phi}}_{k}( {\overset{\sim}{l} - 1} )} + {2{\pi\Delta}\; {f( {k + {1/2}} )}( {N + N_{{CP},l}} )T_{s}}} & {\overset{\sim}{l} > 0}\end{matrix}\mspace{79mu} \overset{\sim}{l}} = 0},1,\ldots \mspace{14mu},{{{M_{rep}^{NPUSCH}N_{RU}N_{slots}^{UL}N_{symb}^{UL}} - {1\mspace{79mu} l}} = {\overset{\sim}{l}\mspace{14mu} {mod}\mspace{14mu} N_{symb}^{UL}}}} } }}} & \lbrack {{Equation}\mspace{14mu} 14} \rbrack\end{matrix}$

In this case, {tilde over (l)} is a symbol counter reset whentransmission starts, and is increased with respect to each symbol duringtransmission.

Table 17 shows an example of SC-FDMA parameters for N_(sc) ^(RU)=1.

TABLE 17 Parameter Δf = 3.75 kHz Δf = 15 kHz N 8192 2048 Cyclic prefixlength 256 160 for l = 0 N_(CP,l) 144 for l = 1,2, . . . ,6 Set ofvalues for k −24,−23, . . . ,23 −6, −5, . . . ,5

SC-FDMA symbols within a slot need to start at l=0 and to be transmittedin an increment sequence of l. In this case, an SC-FDMA symbol l>0starts at time Σ_(l′=0) ^(l-1)(N_(CP,l′)+N)T_(s) within the slot. Withrespect to Δf=3.75 kHz, 2304T_(s) within T_(slot) is not transmitted andis used for a guard period.

Narrowband Physical Random Access Channel (NPRACH)

A physical layer random access preamble is based on a single-subcarrierfrequency-hopping symbol group. A symbol group is shown as a randomaccess symbol group of FIG. 1-8, and has a cyclic prefix having a lengthof T_(CP) and a sequence of 5 identical symbols having a total length ofT_(SEQ). Parameter values are listed in Table 18. The parameter valuesare listed as random access preamble parameters of Table 18.

FIG. 7 shows an example of a random access symbol group.

Table 18 shows an example of random access preamble parameters.

TABLE 18 Preamble format T_(CP) T_(SEQ) 0 2048T_(s) 5 · 8192T_(s) 18192T_(s) 5 · 8192T_(s)

A preamble including 4 symbol groups transmitted without a gap istransmitted N_(rep) ^(NPRACH) times.

When a random access preamble is triggered by a MAC layer, thetransmission of the random access preamble is limited to specific timeand frequency domains.

An NPRACH configuration provided by higher layers includes the follows.

NPRACH resource periodicity N_(period) ^(NPRACH),

Frequency location N_(scoffset) ^(NPRACH) (nprach-SubcarrierOffset) of afirst subcarrier allocated to an NPRACH,

The number of subcarriers N_(sc) ^(NPRACH) (nprach-NumSubcarriers)allocated to an NPRACH,

The number of start subcarriers N_(sc_cont) ^(NPRACH)(nprach-NumCBRA-StartSubcarriers) allocated to contention-based NPRACHrandom access

NPRACH repetition number N_(start) ^(NPRACH) per attempt(nprach-StartTime),

NPRACH start time N_(start) ^(NPRACH) (nprach-StartTime),

Fraction N_(MSG3) ^(NPRACH) (nprach-SubcarrierMSG3-RangeStart) forcalculating a start subcarrier index for an NPRACH subcarrier rangereserved for the indication of UE support to multi-tone msg3transmission

NPRACH transmission may start a N_(start) ^(NPRACH)·30720T_(s) time unitafter the start of a radio frame that fulfills n_(f) mod(N_(period)^(NPRACH)/10)=0. After the transmission of a 4·64(T_(CP)+T_(SEQ)), thegap of a 40·30720T_(s) time unit is inserted.

NPRACH configurations, that is, N_(scoffset) ^(NPRACH)+N_(sc)^(NPRACH)>N_(sc) ^(UL), are not valid.

NPRACH start subcarriers allocated to contention-based a random accessare divided into two sets of subcarriers {0, 1, . . . , N_(sc) _(cont)^(NPRACH)N_(MSG3) ^(NPRACH)−1) and (N_(sc_cont) ^(NPRACH)N_(MSG3)^(NPRACH), . . . , N_(sc) _(cont) ^(NPRACH)−1}. In this case, ifpresent, the second set indicates UE support for multi-tone msg3transmission.

The frequency location of NPRACH transmission is restricted within anN_(sc) ^(RA)=12 subcarrier. Frequency hopping is used within 12subcarriers. In this case, the frequency location of an i^(th) symbolgroup is provided by n_(sc) ^(RA)(i)=n_(start)+ñ_(sc) ^(RA)(i). In thiscase, n_(start)=N_(scoffset) ^(NRPACH)+└n_(init)/N_(sc) ^(RA)┘·N_(sc)^(RA), and Equation 15 is as follows.

$\begin{matrix}{{{\overset{\sim}{n}}_{sc}^{RA}(i)} = \{ \begin{matrix}{( {{{\overset{\sim}{n}}_{sc}^{RA}(0)} + {f( {i/4} )}} ){mod}\mspace{14mu} N_{sc}^{RA}} & {{i\mspace{14mu} {mod}\mspace{14mu} 4} = {{0\mspace{14mu} {and}\mspace{14mu} i} > 0}} \\{{{\overset{\sim}{n}}_{sc}^{RA}( {i - 1} )} + 1} & {{{i\mspace{14mu} {mod}\mspace{14mu} 4} = 1},{{3\mspace{14mu} {and}\mspace{14mu} {{\overset{\sim}{n}}_{sc}^{RA}( {i - 1} )}{mod}\mspace{14mu} 2} = 0}} \\{{{\overset{\sim}{n}}_{sc}^{RA}( {i - 1} )} - 1} & {{{i\mspace{14mu} {mod}\mspace{14mu} 4} = 1},{{3\mspace{14mu} {and}\mspace{14mu} {{\overset{\sim}{n}}_{sc}^{RA}( {i - 1} )}{mod}\mspace{14mu} 2} = 1}} \\{{{\overset{\sim}{n}}_{sc}^{RA}( {i - 1} )} + 6} & {{i\mspace{14mu} {mod}\mspace{14mu} 4} = {{2\mspace{14mu} {and}\mspace{14mu} {{\overset{\sim}{n}}_{sc}^{RA}( {i - 1} )}} < 6}} \\{{{\overset{\sim}{n}}_{sc}^{RA}( {i - 1} )} - 6} & {{i\mspace{14mu} {mod}\mspace{14mu} 4} = {{2\mspace{14mu} {and}\mspace{14mu} {{\overset{\sim}{n}}_{sc}^{RA}( {i - 1} )}} \geq 6}}\end{matrix} } & \lbrack {{Equation}\mspace{14mu} 15} \rbrack \\{{f(t)} = {( {{f( {t - 1} )} + {( {\sum\limits_{n = {{10t} + 1}}^{{10t} + 9}{{c(n)}2^{n - {({{10t} + 1})}}}} ){{mod}( {N_{sc}^{RA} - 1} )}} + 1} ){mod}\mspace{14mu} N_{sc}^{RA}}} & \; \\{{f( {- 1} )} = 0} & \;\end{matrix}$

In this case, ñ_(sc) ^(RA)(0)=n_(init) mod N_(sc) ^(RA) having n_(init)is a subcarrier selected by the MAC layer from {0, 1, . . . , N_(sc)^(NPRACH)−1}. A pseudo-random sequence c(n) is provided by Paragraph 7.2of GPP TS36.211. A pseudo-random sequence generator is initialized asc_(init)=N_(ID) ^(Ncell).

A time-contiguous random access signal s_(l)(t) for a symbol group i isdefined by Equation 16.

$\begin{matrix}{{s_{i}(t)} = {\beta_{NPRACH}e^{j\; 2{\pi {({{n_{SC}^{RA}{(i)}} + {Kk}_{0} + {1/2}})}}\Delta \; {f_{RA}{({t - T_{CP}})}}}}} & \lbrack {{Equation}\mspace{14mu} 16} \rbrack\end{matrix}$

In this case, 0≤t<T_(SEQ)+T_(CP). β_(NPRACH) is a size scaling factorfor following transmit power P_(NPRACH) defined in Paragraph 16.3.1 of3GPP TS 36.213. k₀=−N_(sc) ^(UL)/2, K=Δf/Δf_(RA) describes thedifference of subcarrier spacing between a random access preamble anduplink data transmission. The location of the frequency domaincontrolled by a parameter n_(sc) ^(RA)(i) is derived from Paragraph10.1.6.1 of 3GPP TS36.211. The variable Δf_(RA) is provided by Table 19.

Table 19 shows an example of random access baseband parameters.

TABLE 19 Preamble format Δf_(RA) 0, 1 3.75 kHz

Downlink

A downlink narrowband physical channel corresponds to a set of resourceelements that carry information generated from higher layers, and is aninterface defined between 3GPP TS 36.212 and 3GPP TS 36.211.

The following downlink physical channels are defined.

-   -   Narrowband physical downlink shared channel (NPDSCH)    -   Narrowband physical broadcast channel (NPBCH)    -   Narrowband physical downlink control channel (NPDCCH)

A downlink narrowband physical signal corresponds to a set of resourceelements used by physical layers, but does not carry informationgenerated from higher layers. The following downlink physical signalsare defined:

A narrowband reference signal (NRS)

A narrowband synchronization signal

A narrowband physical downlink shared channel (NPDSCH)

A scrambling sequence generator is initialized asc_(init)=n_(RNTI)·2¹⁴+n_(f) mod 2·2¹³+└n_(s)/2┘+N_(ID) ^(Ncell). In thiscase, n_(s) is the first slot of codeword transmission. In the case ofNPDSCH repetitions and an NPDSCH carrying a BCCH, a scrambling sequencegenerator is initialized again according to expressions described withrespect to each repetition. In the case of the NPDSCH repetitions, whenan NPDSCH does not carry a BCCH, a scrambling sequence generator isinitialized again according to the above-described expressions aftereach min(M_(rep) ^(NPDSCH),4) transmission of codeword having n_(s) andn_(f) configured as the first slot and frame used for repetitiontransmission, respectively.

Modulation is performed using a QPSK modulation method.

An NPDSCH may be mapped to one or more subframes N_(SF), as provided byParagraph 16.4.1.5 of 3GPP TS 36.213. Each of the one or more subframesneeds to be transmitted NPDSCH M_(rep) ^(NPDSCH) times.

With respect to each antenna port used for the transmission of aphysical channel, the blocks y^((p))(0) . . . y^((p))(M_(symb) ^(ap)−1)of complex-value symbols need to be mapped to resource elements (k,l)satisfying all the following criteria in a current subframe.

A subframe is not used for the transmission of an NPBCH, NPSS or NSSS,and

They are assumed to be not used for an NRS by a UE, and

They do not overlap resource elements used for a CRS (if present), and

The index l of the first slot satisfies l l≥l_(DataStart) in a subframe.In this case, l_(DataStart) is provided by Paragraph 16.4.1.4 of 3GPP TS36.213.

In a sequence starting at y^((p))(0), mapping to the resource elements(k,l) through an antenna port p that satisfies the above criteria ofy^((p))(0) . . . y^((p)) (M_(symb) ^(ap)−1) is an increment sequence ofthe first index k and an index l, which start from the first slot of thesubframe and end at the second slot. In the case of an NPDSCH notcarrying a BCCH, after mapping to a subframe,

Before continuing mapping to a next subframe of y^((p))(⋅), M_(rep)^(NPDSCH)−1 part for a subframe is repeated with respect to subframes.Thereafter, the mapping of y^((p))(0), . . . y^((p))(M_(symb) ^(ap)−1)is repeated until M_(rep) ^(NPDSCH)N_(SF) subframes are transmitted. Inthe case of an NPDSCH carrying a BCCH, y^((p))(0), . . . y^((p))(M_(symb) ^(ap)−1) is mapped to N_(SF) subframes as a sequence and isthen repeated until the M_(rep) ^(NPDSCH)N_(SF) subframes aretransmitted.

NPDSCH transmission may be configured by higher layers as transmissiongaps where the NPSDCH transmission is postponed. WhenR_(max)<N_(gap,threshold), a gap is not present in NPDSCH transmission.In this case, N_(gap,threshold) is provided by a higher layer parameterdl-GapThreshold, and R_(max) is provided by 3GPP TS 36.213. A gap startframe and subframe are provided by (10n_(f)+└n_(s)/2┘) modN_(gap,period)=0. In this case, gap periodicity N_(gap,period) isprovided by a higher layer parameter dl-GapPeriodicity. Gap duration ofa plurality of subframes is provided byN_(gap,duration)=N_(gap,coeff)N_(gap,period). In this case,N_(gap,coeff) is provided by a higher layer parameterdl-GapDurationCoeff. In the case of an NPDSCH carrying a BCCH,transmission gaps are not present.

If a subframe is not an NB-IoT downlink subframe, a UE does not expectan NPDSCH a subframe i other the transmission of an NPDSCH carryingSystemInformationBlockType1-NB in a subframe 4. In the case of NPDSCHtransmissions, NPDSCH transmission is postponed up to a next NB-IoTdownlink subframe in subframes not the NB-IoT downlink subframes.

UE Procedure for Receiving NPDSCH

An NB-IoT UE needs to assume a subframe as an NB-IoT DL subframe in thefollowing case.

-   -   A UE determines that a subframe does not include        NPSS/NSSS/NPBCH/NB-SIB1 transmission, and    -   In the case of an NB-IoT carrier in which a higher layer        parameter operationModeInfo is received, a UE obtains        SystemInformationBlockType1-NB and configures a subframe as an        NB-IoT DL subframe.    -   In the case of an NB-IoT carrier in which        DL-CarrierConfigCommon-NB is present, a subframe is configured        as an NB-IoT DL subframe by downlinkBitmapNonAnchor, that is, a        higher layer parameter.

In the case of an NB-IoT UE supporting twoHARQ-Processes-r14, a maximumof 2 downlink HARQ processes need to be present.

When an NPDCCH having the DCI format N1, N2 ended in a subframe nintended for a UE is detected by a given serving cell, the UE needs tostart in a n+5 DL subframe and to decode corresponding NPDSCHtransmission of an N contiguous NB-IoT DL subframe(s) n_(i) having i=0,1, . . . , N−1 for NPDCCH information. In this case,

The subframe n is the last subframe in which an NPDCCH is transmitted,and is determined from the start subframe of NPDCCH transmission and theDCI subframe repetition number field of corresponding DCI;

A subframe(s) ni wherein i=0, 1, . . . , N−1 is N contiguous NB-IoT DLsubframe(s) other than subframes used for SI messages. In this case,n0<n1< . . . , nN−1,

N=N_(Rep)N_(SF). In this case, the value of N_(Rep) is determined by therepetition number field of corresponding DCI. The value of N_(SF) isdetermined by the resource allocation field of corresponding DCI.

k₀ is the number of NB-IoT DL subframe(s) from a DL subframe n+5 to a DLsubframe no. In this case, k₀ is determined by a scheduling delay field(I_(Delay)) with respect to the DCI format N1, and is k₀=0 with respectto the DCI format N2. In the case of DCI CRC scrambled by a G-RNTI, k₀is determined by a scheduling delay field (I_(Delay)) according to Table21. If not, k₀ is determined by a scheduling delay field (I_(Delay))according to Table 20. The value of R_(m,ax) follows Lower Paragraph16.6 of 3GPP 36.213 for a corresponding DCI format N1.

Table 20 shows an example of k₀ for the DCI format N1.

TABLE 20 k₀ I_(Delay) R_(max) < 128 R_(max) ≥ 128 0 0 0 1 4 16 2 8 32 312 64 4 16 128 5 32 256 6 64 512 7 128 1024

Table 21 shows an example of k₀ for the DCI format N1 having a DCI CRCscrambled by a G-RNTI.

TABLE 21 I_(Delay) k₀ 0 0 1 4 2 8 3 12 4 16 5 32 6 64 7 128

After the end of NPUSCH transmission by a UE, the UE does not expect toreceive transmissions in 3 DL subframes.

Resource allocation information of the DCI format N1, N2 (paging) for anNPSICH is indicated by a scheduled UE.

Table 22 shows an example of the number of subframes of an NPDSCH. Thenumber of subframes (N_(SF)) determined by a resource allocation field(I_(SF)) in corresponding DCI according to Table 22.

A repetition number (N_(Rep)) determined by the repetition number field(I_(Rep)) in corresponding DCI according to Table 23.

TABLE 22 I_(SF) N_(SF) 0 1 1 2 2 3 3 4 4 5 5 6 6 8 7 10 

Table 23 shows an example of the repetition number of an NPDSCH.

TABLE 23 I_(REP) N_(REP)  0   1  1   2  2   4  3   8  4  16  5  32  6 64  7  128  8  192  9  256 10  384 11  512 12  768 13 1024 14 1536 152048

The repetition number of an NPDSCH carryingSystemInformationBlockType1-NB is determined based on the parameterschedulingInfoSIB1 configured by higher layers, and follows Table 24.

Table 24 shows an example of the repetition number of an SIB1-NB.

TABLE 24 Value of schedulingInfoSIB1 NPDSCH repetition number  0  4  1 8  2 16  3  4  4  8  5 16  6  4  7  8  8 16  9  4 10  8 11 16 12-15Reserved

A start radio frame for the first transmission of an NPDSCH carryingSystemInformationBlockType1-NB is determined according to Table 125.

Table 25 shows an example of a start radio frame for the firsttransmission of an NPDSCH on which an SIB1-NB is carried.

TABLE 25 Number of Starting radio frame NPDSCH number for NB-SIB1repetitions N_(ID) ^(Ncell) repetitions (nf mod 256)  4 N_(ID) ^(Ncell)mod 4 = 0  0 N_(ID) ^(Ncell) mod 4 = 1 16 N_(ID) ^(Ncell) mod 4 = 2 32N_(ID) ^(Ncell) mod 4 = 3 48  8 N_(ID) ^(Ncell) mod 2 = 0  0 N_(ID)^(Ncell) mod 2 = 1 16 16 N_(ID) ^(Ncell) mod 2 = 0  0 N_(ID) ^(Ncell)mod 2 = 1  1

A start OFDM symbol for an NPDSCH is provided by the indexl_(DataStrart) of the first slot of a subframe k, and is determined asfollows.

-   -   When the subframe k is a subframe used to receive an SIB1-NB,

When the value of the higher layer parameter operationModeInfo is set to‘00’ or ‘01’, I_(DataStrart)=3

Otherwise, I_(DataStrart)=0

-   -   If not,

When the value of a higher layer parameter eutraControlRegionSize ispresent, I_(DataStrart) is provided by a higher layer parametereutraControlRegionSize.

Otherwise, I_(DataStrart)=0

UE Procedure for Reporting ACK/NACK

When NPDSCH transmission intended for a UE and ended in an NB-IoTsubframe n for which ACK/NACK needs to be provided is detected, the useof the NPUSCH format 2 in N contiguous NB-IoT UL slots by the UE needsto be provided and started when n+k₀−1 DL subframe transmission of anNPUSCH carrying an ACK/NACK response is ended. In this case, N=N_(Rep)^(AN)N_(slots) ^(UL), and the value of N_(Rep) ^(AN) is provided by ahigher layer parameter ack-NACK-NumRepetitions-Msg4 configured for anNPRACH resource associated with Msg4 NPDSCH transmission and by a higherlayer parameter ack-NACK-NumRepetitions if not. The value of N_(slots)^(UL) is the number of slots within a resource unit.

A subcarrier allocated for ACK/NACK and the value of k0 are determinedby the ACK/NACK resource field of the DCI format of a correspondingNPDCCH according to Table 16.4.2-1 and Table 16.4.2-2 of 3GPP TS36.213.

Narrowband Physical Broadcast Channel (NPBCH)

A processing structure for a BCH transmission channel follows Paragraph5.3.1 of 3GPP TS 36.212 and has the following differences.

-   -   A transmission time interval (TTI) is 640 ms.    -   The size of a BCH transport block is configured as 34 bits.    -   CRC mask for an NPBCH is selected based on 1 or 2 transmission        antenna ports by an eNodeB according to Table 5.3.1.1-1 of 3GPP        TS 36.212. In this case, the transmission antenna port has been        defined in Section 10.2.6 of 3GPP TS 36.211.    -   The number of rate matching bits has been defined in Section        10.2.4.1 of 3GPP TS 36.211.

Scrambling is performed according to Paragraph 6.6.1 of 3GPP TS 36.211using M_(bit) indicating the number of bits to be transmitted through anNPBCH. M_(bit) is the same as 1600 with respect to a normal cyclicprefix. A scrambling sequence is initialized as c_(init)=N_(ID) ^(Ncell)with respect to radio frames satisfying n_(f) mod 64=0.

Modulation is performed on each antenna port using a QPSK modulationmethod, and is transmitted in a subframe 0 during 64 contiguous radioframes that starts at each radio frame satisfying n_(f) mod 64=0.

Layer mapping and precoding are performed according to Paragraph 6.6.3of 3GPP TS 36.211 wherein PE {1,2}. A UE assumes that antenna portsR₂₀₀₀ and R₂₀₀₁ are used for the transmission of a narrowband physicalbroadcast channel.

The block y^((p))(0), . . . y^((p))(M_(symb)−1) of complex-value symbolsfor each antenna port is transmitted in a subframe 0 during 64contiguous radio frames that start at each radio frame satisfying n_(f)mod 64=and needs to be mapped to elements (k,l) not reserved for thetransmission of reference signals as a sequence starting from contiguousradio frames that start at y(0). An increment sequence is the firstindex k, and a subsequent index l. After the mapping to a subframe,before continuing to perform mapping to the subframe 0 of y^((p))(⋅) ina subsequent radio frame, the subframe is repeated to the subframe 0 in7 subsequent radio frames. The first three OFDM symbols of the subframeare not used in the mapping process. For the mapping purpose, a UEassume narrowband reference signals for antenna ports 2000 and 2001present regardless of an actual configuration and cell-specificreference signals for antenna ports 0-3. The frequency shift of thecell-specific reference signals is calculated by substituting cellN_(ID) ^(cell) with N_(ID) ^(cell) in the calculation of V_(shift) ofParagraph 6.10.1.2 of 3GPP TS 36.211.

Narrowband Physical Downlink Control Channel (NPDCCH)

A narrowband physical downlink control channel carries controlinformation. A narrowband physical control channel is transmittedthrough one or an aggregation of two contiguous narrowband controlchannel elements (NCCEs). In this case, a narrowband control channelelement corresponds to 6 contiguous subcarriers in a subframe. In thiscase, an NCCE 0 occupies subcarriers 0 to 5, and an NCCE 1 occupiessubcarriers 6 to 11. An NPDCCH supports several formats listed in Table1-26. In the case of the NPDCCH format 1, all NCCEs belong to the samesubframe. One or two NPDCCHs may be transmitted within a subframe.

Table 26 shows an example of supported NPDCCH formats.

TABLE 26 NPDCCH format Number of NCCEs 0 1 1 2

Scrambling needs to be performed according to Paragraph 6.8.2 ofTS36.211. A scrambling sequence needs to be initialized at the start ofa subframe k₀ according to Paragraph 16.6 of TS36.213 after every fourthNPDCCH subframe having c_(init)=└n_(s)/2┘2⁹+N_(ID) ^(cell). In thiscase, n_(s) is the first slot of an NPDCCH subframe in which scramblingis (re-) initialized.

Modulation is performed using a QPSK modulation method according toParagraph 6.8.3 of TS36.211.

Layer mapping and precoding is performed according to Paragraph 6.6.3 ofTS36.211 using the same antenna port as that of an NPBCH.

The block y(0), . . . y(M_(symb)−1) of complex-value symbols is mappedas resource elements (k,l) in a sequence that starts at y(0) throughassociated antenna ports that satisfy all the following criteria:

They are the part of an NCCE(s) allocated for NPDCCH transmission, and

They are assumed to be not used for the transmission of an NPBCH, NPSS,or NSSS, and

They are assumed to be not used for an NRS by a UE, and

They do not overlap resource elements used for a PBCH, PSS, SSS, or CRSas defined in Paragraph 6 of TS36.211 (if present), and

The index l of the first slot of a subframe satisfies l≥l_(NPDCCHStart).In this case, l_(NPDCCHStart) is provided by Paragraph 16.6.1 of 3GPP TS36.213.

Mapping to a resource elements (k,l) through an antenna port psatisfying the above-described criteria is an increment sequence of thefirst index k, a subsequent index l that start from the first slot of asubframe and end at the second slot.

NPDCCH transmission may be configured by higher layers havingtransmission gaps where NPDCCH transmission is postponed. Aconfiguration is the same as that described with respect to the NPDSCHof Paragraph 10.2.3.4 of TS36.211.

If a subframe is not an NB-IoT downlink subframe, a UE does not expectan NPDCCH in a subframe i. In the case of NPDCCH transmissions, NPDCCHtransmissions are postponed up to an NB-IoT downlink subframe insubframes not NB-IoT downlink subframes.

DCI Format

DCI Format N0

The DCI format N0 is used for the scheduling of an NPUSCH in one ULcell. The following information is transmitted by the DCI format N0.

Flag for format N0/format N1 distinction (1 bit), subcarrier indication(6 bits), resource allocation (3 bits), scheduling delay (2 bits),modulation and coding method (4 bits), redundancy Version (1 bit), arepetition number (3 bits), a new data indicator (1 bit), a DCI subframerepetition number (2 bits)

DCI Format N1

The DCI format N1 is used for the scheduling of one NPDSCH codeword anda random access procedure initiated by an NPDCCH sequence in one cell.DCI corresponding to the NPDCCH sequence is carried by an NPDCCH. Thefollowing information is transmitted by the DCI format N1:

-   -   Flag for format N0/format N1 distinction (1 bit), NPDCCH        sequence indicator (1 bit)

The format N1 is used for a random access procedure initiated by anNPDCCH sequence only when an NPDCCH sequence indicator is set to “1”, aformat N1 CRC is scrambled as a C-RNTI, and the remaining all fields areconfigured as follows:

-   -   The start number of NPRACH repetitions (2 bits), subcarrier        indication (6 bits) of an NPRACH, and all the remaining bits of        the format N1 are set to 1.

Otherwise,

-   -   Scheduling delay (3 bits), resource allocation (3 bits), a        modulation and coding method (4 bits), a repetition number (4        bits), a new data indicator (1 bit), an HARQ-ACK resource (4        bits), a DCI subframe repetition number (2 bits)

When a format N1 CRC is scrambled as an RA-RNTI, the following field ofthe above fields is reserved.

-   -   A new data indicator, HARQ-ACK resource

When the number of information bits of the format N1 is smaller than thenumber of information bits of the format N0, zero is attached to theformat N1 until a payload size becomes identical with that of the formatN0.

DCI Format N2

The DCI format N2 is used for paging and direct indication. Thefollowing information is transmitted by the DCI format N2.

A flag (1 bit) for paging/direct indication distinction

where flag=0:

-   -   Direct indication information (8 bit), reservation information        bits are added until the size becomes the same size as the size        of the format N2 where flag=1.

where flag=1:

-   -   Resource allocation (3 bits), a modulation and coding method (4        bits), a repetition number (4 bits), a DCI subframe repetition        number (3 bits)

NPDCCH-Related Procedure

A UE needs to monitor an NPDCCH candidate set configured by higher layersignaling for control information. In this case, the monitoring meansthat an attempt is made to decode each of NPDCCHs within a set accordingto all monitored DCI formats.

An NPDCCH search space NS_(k) ^((L′,R)) within an aggregation levelL′∈{1, 2} and a repetition levelR∈{1,2,4,8,16,32,64,128,256,512,1024,2048} is defined by a set of NPFCCHcandidates. In this case, each candidate is repeated as a set of Rcontiguous NB-IoT downlink subframes other than subframes used for thetransmission of SI messages that start in a subframe k.

The location of the start subframe k is provided by k=k_(b). In thiscase, k=k_(b) is a b-th contiguous NB-IoT DL subframe in a subframe k0other than subframes used for the transmission of SI messages b=u·R,

${u = 0},1,\ldots \mspace{14mu},{\frac{R_{\max}}{R} - 1},$

and the subframe k0 is a subframe that satisfies a condition(10n_(f)+└n_(s)/2┘ mod T)=└α_(offset)·T┘. In this case, T=R_(max)·G,T≥4. G and α_(offset) are provided by a higher layer parameter.

With respect to a type 1-NPDCCH common search space, k=k0, and isdetermined from the locations of NB-IoT paging opportunity subframes.

When a UE is configured as an NB-IoT carrier by higher layers in orderto monitor an NPDCCH UE-specific search space,

The UE monitors the NPDCCH UE-specific search space through the NB-IoTcarrier configured by higher layers,

The UE does not expect to receive an NPSS, NSSS, NPBCH through theNB-IoT carrier configured by higher layers.

Otherwise,

The UE monitors the NPDCCH UE-specific search space through the sameNB-IoT carrier in which an NPSS/NSSS/NPBCH has been detected.

In the first slot of a subframe k, a start OFDM symbol for an NPDCCHprovided by an index l_(NPDCCHStart) is determined as follows.

If a higher layer parameter eutraControlRegionSize is present,

l_(NPDCCHStart) is provided by a higher layer parametereutraControlRegionSize.

Otherwise, l_(NPDCCHStart)=0

Narrowband Reference Signal (NRS)

Before a UE obtains operationModeInfo, the UE may assume that narrowbandreference signals are transmitted in a subframe #9 not including an NSSSand in subframes #0 and #4.

When the UE receives the higher layer parameter operationModeInfoindicating a guard band or standalone,

Before the UE obtains SystemInformationBlockType1-NB, the UE may assumethat narrowband reference signals are transmitted in a subframe #9 notincluding an NSSS and subframes #0, #1, #3, #4.

After the UE obtains SystemInformationBlockType1-NB, the UE may assumethat narrowband reference signals are transmitted in the subframe #9 notincluding an NSSS, the subframes #0, #1, #3, #4, and an NB-IoT downlinksubframe, and does not expect narrowband reference signals in otherdownlink subframes.

When a UE receives a higher layer parameter operationModeInfo indicatinginband-SamePCI or inband-Different PCI,

Before the UE obtains SystemInformationBlockType1-NB, the UE may assumethat narrowband reference signals are transmitted in a subframe #9 notincluding an NSSS and subframes #0, #4.

After the UE obtains SystemInformationBlockType1-NB, the UE may assumethat narrowband reference signals are transmitted in the subframe #9 notincluding an NSSS, the subframes #0, #4, and an NB-IoT downlinksubframe, and does not expect narrowband reference signals in otherdownlink subframes.

Narrowband Primary Synchronization Signal (NPSS)

A sequence d_(l)(n) used for a narrowband primary synchronization signalis generated from the Zadoff-Chu sequence of a frequency domainaccording to Equation 17.

$\begin{matrix}{{{d_{l}(n)} = {{S(l)} \cdot e^{{- j}\frac{\pi \; {{un}{({n\; + 1})}}}{11}}}},{n = 0},1,\ldots \mspace{14mu},10} & \lbrack {{Equation}\mspace{14mu} 17} \rbrack\end{matrix}$

In this case, a Zadoff-Chu root sequence index u=5 and S(l) fordifferent symbol indices l is provided in Table 27.

Table 27 shows an example of S(l).

TABLE 27 Cyclic prefix length S(3), . . . , S(13) Normal 1 1 1 1 −1 −1 11 1 −1 1

The same antenna port needs to be used for all the symbols of anarrowband primary synchronization signal within a subframe.

A UE should not assume that a narrowband primary synchronization signalis transmitted through the same antenna port as a given downlinkreference signal. The UE should not assume that the transmissions of anarrowband primary synchronization signal in a given subframe use thesame antenna port or ports as a narrowband primary synchronizationsignal in given other subframes.

A sequences di(n) needs to be mapped to resource elements (k,l) as anincrement sequence of the first index k=0, 1, . . . , N_(sc) ^(RB)−2 anda subsequent index=3, 4, . . . , 2N_(symb) ^(DL)−1 in a subframe 5within all radio frames. With respect to resource elements (k,l)overlapping resource elements in which a cell-specific reference signalsis transmitted, a corresponding sequence element d(n) is not used for anNPSS, but is counted as a mapping process.

Narrowband Secondary Synchronization Signals (NSSS)

A sequence d(n) used for a narrowband secondary synchronization signalis generated from a frequency domain Zadoff-Chu sequence according toEquation 18.

$\begin{matrix}{{d(n)} = {{b_{q}(n)} \cdot e^{{- j}\; 2{\pi\theta}_{f}n} \cdot e^{{- j}\frac{\pi \; {{un}^{\prime}{({n^{\prime} + 1})}}}{131}}}} & \lbrack {{Equation}\mspace{14mu} 18} \rbrack\end{matrix}$

In this case,

n = 0, 1, …  , 131 n^(′) = n  mod  131 m = n  mod  128u = N_(ID)^(Ncell)  mod  126 + 3$q = \lfloor \frac{N_{ID}^{Ncell}}{126} \rfloor$

A binary sequence b_(q)(n) is provided by Table 28. The cyclic shiftθ_(f) of a frame number n_(f) is provided by

$\theta_{f} = {\frac{33}{132}( {n_{f}/2} )\mspace{14mu} {mod}\mspace{14mu} 4.}$

Table 28 shows an example of b_(q)(n).

TABLE 28 q b_(q) (0), . . . , b_(q) (127) 0 [1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1] 1 [1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 1 −1−1 1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1 −1 1 1−1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1−1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1−1 −1 1 −1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1] 2 [1 −1 −1 1 −1 1 1 −1−1 1 1 −1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1−1 −1 1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1 1 −1−1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1−1 −1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 −1 1 1 −11 −1 −1 1] 3 [1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 1 −1 −11 1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1−1 1 1 −1 −1 1 1 −1 1 −1 −1 1 −1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1 1−1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1 −1 1 1 −1 1 −1−1 1 −1 1 1 −1 1 −1 −1 1 1 −1 −1 1 −1 1 1 −1]

The same antenna port needs to be used by all the symbols of anarrowband secondary synchronization signal within a subframe.

A UE should not assume that a narrowband secondary synchronizationsignal is transmitted through the same antenna port as a given downlinkreference signal. The UE should not assume that the transmissions of anarrowband secondary synchronization signal in a given subframe uses thesame antenna port or ports as the narrowband secondary synchronizationsignal of a given another subframe.

A sequence d(n) should be mapped to resource elements (k,l) as asequence starts at d(0) in the sequence of the first index k through 12allocated subcarriers and then the sequence of an index l through thelast N_(symb) ^(NSSS) symbols allocated in radio frames to satisfy n_(f)mod 2=0. In this case, N_(symb) ^(NSSS) is provided by Table 29.

Table 29 shows an example of the number of NSSS symbols.

TABLE 29 Cyclic prefix length N_(symb) ^(NSSS) Normal 11

Generation of OFDM Baseband Signal

If the higher layer parameter operationModeInfo does not indicates“inband-SamePCI” and samePCI-Indicator does not indicate “samePCI”, thetime-contiguous signal s_(l) ^((p))(t) through the antenna port p of anOFDM symbol l in a downlink slot is defined by Equation 19.

$\begin{matrix}{{s_{l}^{(p)}(t)} = {\sum\limits_{k = {- {\lfloor{N_{sc}^{RB}/2}\rfloor}}}^{{\lceil{N_{sc}^{RB}/2}\rceil} - 1}{a_{k^{( - )},l}^{(p)} \cdot e^{j\; 2{\pi {({k + \frac{1}{2}})}}\Delta \; {f{({t - {N_{{CP},i}T_{s}}})}}}}}} & \lbrack {{Equation}\mspace{14mu} 19} \rbrack\end{matrix}$

0≤t<(N_(CP,i)+N)×T_(s). In this case, k⁽⁻⁾=k+└N_(sc) ^(RB)/2┘, N=2048,Δf=15 kHz, and a_(k,l) ^((P)) is the contents of a resource element(k, 1) through an antenna port.

When the higher layer parameter operationModeInfo indicates“inband-SamePCI” or samePCI-Indicator indicates “samePCI”, thetime-contiguous signal s_(l) ^((p))(t) through the antenna port p of anOFDM symbol l′. In this case, l′=l+N_(symb) ^(DL)(n_(s) mod 4)∈{0, . . ., 27} is an OFDM symbol index in at the start of the last even-numberedsubframe, and is defined by Equation 20.

$\begin{matrix}{{s_{l}^{(p)}(t)} = {\sum\limits_{k = {- {\lfloor{N_{RB}^{DL}{N_{sc}^{RB}/2}}\rfloor}}}^{- 1}{e^{\theta_{k^{( - )}}} {a_{k^{( - )},l}^{(p)} \cdot {\quad{e^{j\; 2\pi \; k\; \Delta \; {f({t - {N_{{CP},{l^{\prime}{mod}\mspace{14mu} N_{symb}^{DL}}}T_{s}}})}} + {\sum\limits_{k = 1}^{\lceil{N_{RB}^{DL}{N_{sc}^{RB}/2}}\rceil}{e^{\theta_{k^{( + )}}} {a_{k^{( + )},l}^{(p)} \cdot e^{j\; 2\pi \; k\; \Delta \; {f({t - {N_{{CP},{l^{\prime}{mod}\mspace{14mu} N_{symb}^{DL}}}T_{s}}})}}}}}}}}}}} & \lbrack {{Equation}\mspace{14mu} 20} \rbrack\end{matrix}$

0≤t<(N_(CP,i)+N)×T_(s). In this case, if k⁽⁻⁾=k+└N_(RB) ^(DL)/2┘ andk⁽⁺⁾=k+└N_(RB) ^(DL)N_(sc) ^(RB)/2┘−1 and a resource element (k,l′) isused for narrowband IoT, θ_(k,l′)=j2πf_(NB-IoT)T_(s)(N+Σ_(i=0)^(l′)N_(CP,i mod 7)), and otherwise is 0. f_(NB-IoT) is a value obtainedby subtracting the center frequency location of an LTE signal from thefrequency location of a carrier of a narrowband IoT PRB.

In specific 3GPP spec., only a normal CP is supported for narrowband IoTdownlink.

Hereinafter, a physical layer process of a narrowband physical broadcastchannel (NPBCH) is described more specifically.

Scrambling

Scrambling is performed according to Paragraph 6.6.1 of 3GPP TS 36.211using M_(bit) indicating the number of bits to be transmitted through anNPBCH. M_(bit) is the same as 1600 for a normal cyclic prefix. Ascrambling sequence is initialized as c_(init)=N_(ID) ^(Ncell) in radioframes that satisfy n_(f) mod 64=0.

Modulation

Modulation is performed using the modulation method of Table 10.2.4.2-1according to Paragraph 6.6.2 of TS36.211.

Table 30 shows an example of a modulation method for an NPBCH.

TABLE 30 Physical channel Modulation methods NPBCH QPSK

Layer Mapping and Precoding

Layer mapping and precoding is performed according to Paragraph 6.6.3 of3GPP TS 36.211 where P∈{1,2}. A UE assumes that antenna ports R₂₀₀₀ andR₂₀₀₁ are used for the transmission of a narrowband physical broadcastchannel.

Mapping to Resource Elements

A block y^((p))(0), . . . y^((p))(M_(symb)−1) of complex-value symbolsfor each antenna port needs to be transmitted in a subframe 0 during 64contiguous radio frames that start at each radio frame satisfying n_(f)mod 64=and needs to be mapped to elements (k,l) not reserved for thetransmission of reference signals starting from contiguous radio framesthat start at y(0) as a sequence, and needs to be an increment sequenceof the first index k, a subsequent index l. After the mapping to thesubframe, before continuing to mapping to a subframe 0 of y^((p))(⋅) ina subsequent radio frame, a subframe is repeated to a subframe 0 insubsequent 7 radio frames. The first three OFDM symbols of the subframeare not used for a mapping process.

For the mapping purpose, a UE assumes narrowband reference signals forantenna ports 2000 and 2001 present regardless of an actualconfiguration and cell-specific reference signals for antenna ports 0-3.The frequency shift of the cell-specific reference signals is calculatedby substituting cell N_(ID) ^(cell) with N_(ID) ^(Ncell) in thecalculation of V_(shift) of Paragraph 6.10.1.2 of 3GPP TS 36.211.

Information related to an MIB-NB and an SIBN1-NB is described morespecifically.

MasterInformationBlock-NB

MasterInformationBlock-NB includes system information transmittedthrough a BCH.

Signaling radio bearer: N/A

RLC-SAP: TM

Logical channel: BCCH

Direction: E-UTRAN to UE

Table 31 shows an example of a MasterInformationBlock-NB format.

TABLE 31 -- ASN1START MasterInformationBlock-NB ::= SEQUENCE {systemFrameNumber-MSB-r13 BIT STRING (SIZE (4)), hyperSFN-LSB-r13 BITSTRING (SIZE (2)), schedulingInfoSIB1-r13 INTEGER (0..15),systemInfoValueTag-r13 INTEGER (0..31), ab-Enabled-r13 BOOLEAN,operationModeInfo-r13 CHOICE { inband-SamePCI-r13 Inband-SamePCI-NB-r13,inband-Different PCI-r13 Inband-Different PCI-NB-r13, guardband-r13Guardband-NB-r13, standalone-r13 Standalone-NB-r13 }, spare BIT STRING(SIZE (11)) } ChannelRasterOffset-NB-r13 ::= ENUMERATED {khz−7dot5,khz−2dot5, khz2dot5, khz7dot5} Guardband-NB-r13 ::= SEQUENCE {rasterOffset-r13 ChannelRasterOffset-NB-r13, spare  BIT STRING (SIZE(3)) } Inband-SamePCI-NB-r13 ::= SEQUENCE { eutra-CRS-SequenceInfo-r13INTEGER (0..31) } Inband-Different PCI-NB-r13 ::= SEQUENCE {eutra-NumCRS-Ports-r13 ENUMERATED {same, four}, rasterOffset-r13ChannelRasterOffset-NB-r13, spare BIT STRING (SIZE (2)) }Standalone-NB-r13 ::= SEQUENCE { spare BIT STRING (SIZE (5)) } --ASN1STOP

Table 32 shows the description of the MasterInformationBlock-NB field.

TABLE 32 MasterInformationBlock-NB field descriptions ab-Enabled A valueTRUE indicates that a UE should obtain SystemInformationBlockType14-NBbefore an RRC connection configuration or resumption is initiated andaccess barring is enabled. eutra-CRS-SequenceInfo Information of acarrier including an NPSS/NSSS/NPBCH. Each value is associated with anE-UTRA PRB index as an offset in the middle of an LTE system arranged bya channel raster offset. eutra-NymCRS-Ports The number of E-UTRA CRSantenna ports. A port or 4 antenna ports having the same number of NRSs.hyperSFN-LSB Indicate two least significant bits of a Hyper SFN. Theremaining bits are present in SystemInformationBlockType1-NB.operationModeInfo Refer to a deployment scenario (in-band/guardband/standalone) and related information TS 36.211 [21] and TS 36.213[23]. Inband-SamePCI indicates in-band deployment, and an NB-IoT and LTEcell share the same physical cell ID and have the same number of NRSsand CRS ports. Inband-Different PCI indictaes in-band deployment, and anNB-IoT and LTE cell have different physical cell IDs. Guardbandindicates guard band deployment. Standalone indicates standalonedeployment. rasterOffset an NB-IoT offset from LTE channel raster. Unitof kHz of a set {−7.5, −2.5, 2.5, 7.5}. schedulingInfoSIB1 This fieldincludes indices of a table defined in TS 36.213 [23, Table 16.4.1.3-3]that defines SystemInformationBlockType1-NB scheduling information.systemFrameNumber-MSB Defines four most significant bits of an SFN. Asindicated in TS 36.211 [21], six least significant bits of an SFN areimplicitly obtained by decoding an NPBCH. systemInfoValueTag Common forall SIBs other than an MIB-NB, SIB14-NB and SIB16-NB.

System InformationBlockType1-NB

A SystemInformationBlockType1-NB message includes related informationwhen evaluating whether a UE is permitted to access a cell, and definesthe scheduling of other system information.

Signalling radio bearer: N/A

RLC-SAP: TM

Logical channel: BCCH

Direction: E-UTRAN to UE

Table 33 shows an example of the SystemInformationBlockType1 (SIB1)-NBmessage.

TABLE 33 -- ASN1START SystemInformationBlockType1-NB ::= SEQUENCE {hyperSFN-MSB-r13 BIT STRING (SIZE (8)), cellAccessRelatedInfo-r13SEQUENCE { plmn-IdentityList-r13 PLMN-IdentityList-NB-r13,trackingAreaCode-r13 TrackingAreaCode, cellIdentity-r13 CellIdentity,cellBarred-r13 ENUMERATED {barred, notBarred}, intraFreqReselection-r13ENUMERATED {allowed, notAllowed} }, cellSelectionInfo-r13 SEQUENCE {q-RxLevMin-r13 Q-RxLevMin, q-QualMin-r13 Q-QualMin-r9 }, p-Max-r13 P-MaxOPTIONAL, -- Need OP freqBandIndicator-r13 FreqBandIndicator-NB-r13,freqBandInfo-r13 NS-PmaxList-NB-r13 OPTIONAL, -- Need ORmultiBandInfoList-r13 MultiBandInfoList-NB-r13 OPTIONAL, -- Need ORdownlinkBitmap-r13 DL-Bitmap-NB-r13 OPTIONAL, --Need OP,eutraControlRegionSize-r13 ENUMERATED {n1, n2, n3} OPTIONAL, -- Condinband nrs-CRS-PowerOffset-r13 ENUMERATED {dB−6, dB−4dot77, dB−3,dB−1dot77, dB0, dB1, dB1dot23, dB2, dB3, dB4, dB4dot23, dB5, dB6, dB7,dB8, dB9} OPTIONAL, -- Cond inband-SamePCI schedulingInfoList-r13SchedulingInfoList-NB-r13, si-WindowLength-r13 ENUMERATED {ms160,ms320, ms480, ms640, ms960, ms1280, ms1600, spare1},si-RadioFrameOffset-r13 INTEGER (1..15) OPTIONAL, -- Need OPsystemInfoValueTagList-r13 SystemInfoValueTagList-NB-r13 OPTIONAL, --Need OR lateNonCriticalExtension OCTET STRING OPTIONAL,nonCriticalExtension SEQUENCE { } OPTIONAL } PLMN-IdentityList-NB-r13::= SEQUENCE (SIZE (1..maxPLMN-r11)) OF PLMN-IdentityInfo- NB-r13PLMN-IdentityInfo-NB-r13 ::= SEQUENCE { plmn-Identity-r13 PLMN-Identity,cellReservedForOperatorUse-r13 ENUMERATED {reserved, notReserved},attachWithoutPDN-Connectivity-r13 ENUMERATED {true} OPTIONAL -- Need OP} SchedulingInfoList-NB-r13 ::= SEQUENCE (SIZE(1..maxSI-Message-NB-r13)) OF SchedulingInfo- NB-r13SchedulingInfo-NB-r13::= SEQUENCE { si-Periodicity-r13 ENUMERATED {rf64,rf128, rf256, rf512, rf1024, rf2048, rf4096, spare},si-RepetitionPattern-r13 ENUMERATED {every2ndRF, every4thRF, every8thRF,every16thRF}, sib-MappingInfo-r13 SIB-MappingInfo-NB-r13, si-TB-r13ENUMERATED {b56, b120, b208, b256, b328, b440, b552, b680} }SystemInfoValueTagList-NB-r13 ::= SEQUENCE (SIZE (1..maxSI-Message-NB-r13)) OF SystemInfoValueTagSI-r13SIB-MappingInfo-NB-r13 ::= SEQUENCE (SIZE (0..maxSIB-1)) OFSIB-Type-NB-r13 SIB-Type-NB-r13 ::= ENUMERATED { sibType3-NB-r13,sibType4-NB-r13, sibType5-NB-r13, sibType14-NB-r13, sibType16-NB-r13,spare3, spare2, spare1} -- ASN1STOP

Table 34 shows the description of the SystemInformationBlockType1-NBfield.

TABLE 34 SystemInformationBlockType1-MB field descriptionsattachWithoutPDN-COnnectivity If present, the field indicates thatattach is supported without a PDN connection specified in TS 24.301 [35]with respect to such a PLMN. cellBarred Barr means that a cell is barredas defined in TS 36.304 [4]. cellIdentity Indicate a cell identity.cellReservedForOperatorUse The same as that defined in TS 36.304 [4].cellSelectionInfo Cell selection information, such as that defined in TS36.304 [4]. downlinkBitmapNB-IoT downlink subframe configuration fordownlink transmission. If a bitmap is not present, as specified in TS36.213[23], a UE assumes that all subframes are valid (other thansubframes on which an NPSS/NSSS/NPBCH/SIB1-NB is carried).eutraControlRegionSize Indicate the control area size of an E-UTRA cellfor an in-band operation mode. A unit is the number of OFDM symbols.freqBandIndicator A list, such as that defined in TS 36.101 [42, Table6.2.4-1], with respect to the frequency band of freqBandIndicatorfreqBandInfo A list of additionalPmax and additionalSpectrumEmission,such as that defined in TS 36.101 [42, Table 6.2.4-1], with respect tothe frequency band of freqBandIndicator. hyperSFN-MSB Indicate eightmost significant bits of a hyper-SFN. A complete hyper-SFN isconstructed along with the hyper SFN-LSB of an MIB-NB. The hyper-SFN isincreased one by one when the SFN wraps around. intraFreqReselection Asdefined in TS 36.304 [4], treated as being barred by a UE or if the mostsignificant rank cell is barred, it is used to control cell reselectionthrough intra-frequency cells. multiBandInfoList As defined in TS 36.101[42, Table 5.5-1], additional frequency band indicators, a list ofadditionalPmax and additionalSpectrumEmission values. If a UE supportsthe frequency band of a freqBandIndicator IE, the frequency band isapplied. Otherwise, the first listed band supported by a UE in amultiBandInfoList IE is applied. nts-CRS-PowerOffset an NRS power offsetbetween an NRS and an E-UTRA CRS. dB unit, a default value of 0.plmn-IdentityList A list of PLMN indentities. The first listedPLMN-Identity is a primary PLMN. p-Max A value applicable to a cell. Ifnot present, a UE applies maximum power according to the UE capability.q-QualMin A parameter “Qqualmin” of TS 36.304 [4]. q-RxLevMin Aparameter Qrxlevmin of TS 36.304 [4]. An actual value Qrxlevmin = IEvalue * 2 [dB]. schedulingInfoList Indicate additional schedulinginformation of SI messages. si-Periodicity Periodicity of an SI-messageof a radio frame. For example, rf256 indicates 256 radio frames, rf512denotes 512 radio frame, etc. si-RadioFrameOffset The offset of a radioframe number for calculating the start of an SI window. If the field isnot present, an offset is not applied. si-RepetitionPattern Indicatestart radio frames within an SI window used for SI message transmission.A value very2ndRF corresponds to all second radio frames starting fromthe first radio frame of an SI window used for SI transmission, and avalue every4thRF corresponds to a fourth radio frame, etc. si-TB Thisfield indicates on SI transport block size as the number of bits used tobroadcast a message. si-WindowLength A common SI scheduling window forall SIs. In this case, ms160 indicates 160 milliseconds, and ms320indicates 320 millisecond, etc. sib-MappingInfo A list of SIBs mapped tosuch a SystemInformation message. Mapping information of an SIB2 is notpresent; this is always present in the first SystemInformation messagelisted in the schedulingInfoList list. systemInfoValueTagList IndicateSI message-specific value tags. As in SchedulingInfoList, this includesthe entries of the same number and is listed as the same side sequence.systemInfoValueTagSI An SI message-specific value tag, such as thatspecified in 5.2.1.3. Common to all SIBs within an SI message other thanSIB14. trackingAreaCode trackingAreaCode common to all PLMNs is listed.

TABLE 35 Conditional presence Description inband When an IEoperationModeInfo of an MIB-NB is configured as inband-SamePCI orinband-Different PCI, the field is mandatory. Otherwise, the field isnot present. inband-SamePCI When an IE operationModeInfo of an MIB-NB isconfigured as inband- SamePCI, the field is mandatory. Otherwise, thefield is not present.

The abbreviations and definition of terms to be described are arrangedprior to the description of a method of transmitting and receivingSIB1-NBs in a TDD NB-IoT system proposed in this specification.

Abbreviation

MIB-NB: masterinformationblock-narrowband

SIB1-NB: systeminformationblock1-narrowband

CRS: cell specific reference signal or common reference signal

ARFCN: absolute radio-frequency channel number

PRB: physical resource block

PRG: precoding resource block group

PCI: physical cell identifier

N/A: non-applicable

EARFCN: E-UTRA absolute radio frequency channel number

RRM: radio resource management

RSRP: reference signal received power

RSRQ: reference signal received quality

TBS: transport block size

TDD/FDD: time division duplex/frequency division duplex

Definition

NB-IoT: NB-IoT enables access to a network service through an E-UTRAusing a channel bandwidth limited to 200 kHz.

NB-IoT inband operation: NB-IoT operates as an inband using a resourceblock(s) within a normal E-UTRA carrier.

NB-IoT a guard band operation: NB-IoT operates as a guard band when aresource block(s) not used within the guard band of an E-UTRA carrier isused.

NB-IoT standalone operation: NB-IoT operates as standalone when its ownspectrum is used. For example, a spectrum used by a current GERAN systeminstead of one or more GSM carriers and a scattered spectrum forpotential IoT deployment.

Anchor carrier: a carrier in which an NPSS/NSSS/NPBCH is transmittedwith respect to TDD or an NPSS/NSSS/NPBCH/SIB-NB is transmitted withrespect to FDD by a user equipment in NB-IoT.

Non-anchor carrier: a carrier in which an NPSS/NSSS/NPBCH/SIB-NB is nottransmitted with respect to FDD or an NPSS/NSSS/NPBCH is not transmittedwith respect to TDD by a user equipment in NB-IoT.

Channel raster: a minimum unit by which a user equipment reads aresource. In the case of an LTE system, channel raster has a value of100 kHz.

Furthermore, “/” described in this specification may be interpreted as“and/or.” “A and/or B” may be interpreted as the same meaning as“includes at least one of A or (and/or) B.”

A method of transmitting an SIB1-NB in a TDD NB-IoT system proposed inthis specification hereinafter is described more specifically.

A method proposed in this specification includes a concept in which anSIB1-NB is transmitted on a third carrier not an anchor-carrier.

The third carrier may be referred to as the above-described non-anchorcarrier.

Furthermore, a method proposed in this specification includes a seriesof procedures related to the interpretation of a message included in anSIB1-NB.

A method proposed in this specification is described based on an NB-IoTsystem, for convenience of description, but may be applied to othercommunication systems having low energy/low costs, such as MTC andenhanced MTC (eMTC).

In this case, in a method proposed in this specification, a channel, aparameter, etc. described in this specification may be differentlydefined or represented depending on the characteristics of each system.

Furthermore, an overall description or procedure, etc. of theabove-described NB-IoT may be applied to materialize a method proposedin this specification.

A method of transmitting an SIB1-NB proposed in this specification isbasically configured with (1) a carrier location where systeminformation is transmitted, (2) a subframe location and repetitionnumber where an SIB1-NB is transmitted, (3) a subframe location where anNRS may be expected without system information, (4) the interpretationand configuration of an SIB1-NB message, (5) an operation related to theRRM or CE level of a user equipment when system information istransmitted on a non-anchor carrier, (6) a DL/UL non-anchor carrierconfiguration and (7) the number of NRS and CRS ports when an SIB1-NB istransmitted on a non-anchor carrier.

Carrier Location where System Information May be Transmitted

First, a carrier location where system information may be transmitted isdescribed.

If a downlink subframe is not sufficient depending on an UL/DLconfiguration, a base station may transmit system information (e.g., anSIB1-NB and the remaining other SIBx-NBs separately) to a user equipmenton a non-anchor carrier.

This may be limitedly allowed only in a specific UL/DL configurationand/or may be limitedly allowed for a specific operation mode onlyand/or may be limitedly allowed for only specific some repetitionnumbers of an SIB1-NB and/or may be limitedly allowed depending on thenumber of cell specific reference signal (CRS) and narrowband referencesignal (NRS) antenna ports.

The specific UL/DL configuration may be an UL/DL configuration in whichtwo or more downlink subframes are not present other than subframes #0,5, 9 and a special subframe, for example.

The specific operation mode may be an in-band operation mode, forexample.

The specific some repetition numbers of the SIB1-NB are values derivedby schedulingInfoSIB1. For example, in repetition numbers 4 and 8, thetransmission of an SIB1-NB on a non-anchor carrier may not be permitted.

Furthermore, when an SIB1-NB is transmitted on a non-anchor carrier, therepetition number of an SIB1-NB on a non-anchor carrier or the number ofsubframes used for SIB1-NB transmission during a specific section may bedifferently interpreted depending on schedulingInfoSIB1 informationwithin an MIB-NB and a carrier location where an SIB1-NB is transmitted.

If an SIB1-NB is transmitted on a non-anchor carrier as described above,this may be basically divided into two types as follows.

(1) When an SIB1-NB is transmitted on a non-anchor carrier only

(2) When an SIB1-NB is transmitted on both an anchor-carrier and anon-anchor carrier

When an SIB1-NB is transmitted on a carrier not an anchor-carrier, theoperation mode of an MIB-NB may be identically applied to the carrier ofthe SIB1-NB and/or a carrier on which the remaining other SIBx-NBs aretransmitted.

The same is true of an operation mode and all types of informationwithin 7-bits operationModeInfo.

Furthermore, the remaining SIBx-NB not an SIB1-NB may be transmitted ina specific one non-anchor carrier.

Carrier location information of an SIB1-NB and the remaining otherSIBx-NB carrier location information may be included in an MIB-NB andSIB1-NB, respectively.

The MIB-NB and the SIB1-NB are not notified in a form, such asARFCN-ValueEUTRA, because they may not be transmitted using sufficientdownlink resources like the remaining other SIBx-NBs.

A carrier location where an SIB1-NB is transmitted may be defined as arelative PRB location (one of one or more pre-determined offset values)with an anchor-carrier.

Furthermore, a carrier location where the remaining SIBx-NBs aretransmitted may be defined as a relative PRB location with ananchor-carrier (one of one or more pre-determined offset values and therange of the offset values may be the same as or different from therange of an offset value for providing notification of an SIB1-NBtransmission location) or may be defined a relative PRB location with acarrier where an SIB1-NB is transmitted.

In this case, when an SIB1-NB is transmitted on both an anchor-carrierand a non-anchor carrier, a base station may first provide notificationof a relative PRB location of the anchor-carrier with the location ofthe non-anchor carrier (on which the SIB1-NB is transmitted).

This may be similarly applied to a guardband operation mode and astandalone operation mode.

That is, the guardband and standalone operation modes are used as a unitin which an PRB concept indicates a unit of 180 kHz, and may be used toexpress a relative location between carriers as described above.

In general, this may be different from a case where a channel number ofa form, such as ARFCN-ValueEUTRA, is used when a non-anchor carrier isconfigured in an NB-IoT system.

Furthermore, in providing notification of the carrier location of anSIB1-NB, in order to provide notification of the carrier location in anMIB-NB as a relative PRB interval with an anchor-carrier, the number ofcarriers on which an SIB1-NB may be transmitted may need to be limited.

In this case, when the resource allocation of an LTE system isconsidered (e.g., when the unit of a PRG and RBG is considered), anon-anchor carrier on which an SIB1-NB may be transmitted needs toinclude at least one high value and one low value from the viewpoint ofthe frequency rather than an anchor carrier.

The same is true of a case where an SIB1-NB may be transmitted on anon-anchor carrier in the guardband operation mode.

Of course, the same is true of a case where an SIB1-NB may betransmitted on a non-anchor carrier even in the standalone operationmode.

For example, in the case of an n-band operation mode, if the location ofan anchor-carrier corresponds to a PRB k-th within an LTE system band, anon-anchor carrier location on which an SIB1-NB may be transmitted needsto include at least one value smaller than k and at least one valuegreater than k.

If two PRB locations lower than k and two PRB locations higher than kare included in a non-anchor carrier on which an SIB1-NB may betransmitted, the PRB index of the non-anchor carrier on which an SIB1-NBmay be transmitted may be represented as a sequence {k−k1, k−k2, k+k3,k+k4} from a low PRB number.

In this case, “2” is only an embodiment and may be a value greater thananother value 1 or 2. Furthermore, the numbers of non-anchor carriers onwhich the SIB1-NBs of a PRB location lower than k and a PRB locationlower than k may be transmitted may not be the same.

In this case, k1 and k2, k3, k4 may not have a specific relation.

However, the numbers may be defined to have values, such as “k1 and k4.”Likewise, the numbers may be defined to have values, such as “k2 andk3.”

In other words, {k−k1, k−k2, k+k2, k+k1} is obtained, and k1 and k2 maybe contiguous values, but k2 may be a value smaller than 1.

The reason for this is that a base station does not want to use N PRBsneighboring an anchor-carrier for the power boosting of theanchor-carrier.

If such a limit is not present, k1 and k2 may be selected as 2 and 1,respectively.

As described above, an MIB-NB may indicate a carrier location k′ wherean SIB1-NB is transmitted within a non-anchor carrier set on which theSIB1-NB may be transmitted.

This may be implemented by newly adding an independent field within theMIB-NB.

Furthermore, k1 and k2 (also k3 and k4) may be configured as differentvalues depending on the operation mode of an anchor-carrier or theoperation mode of a non-anchor carrier on which an SIB1-NB istransmitted or the operation mode of an anchor-carrier and the operationmode of a non-anchor carrier on which an SIB1-NB is transmitted.

In the description, in a specific filed of an MIB-NB used to indicatethe carrier location of an SIB1-NB, one state may mean that the SIB1-NBis transmitted on an anchor carrier.

Alternatively, an independent one field-A (e.g., defined as 1 bit) maybe used to provide notification of whether an SIB1-NB is transmitted onan anchor carrier.

In such a case, whether a field-B (different information configured as 1bit or more) is present or an interpretation method of the field-B maybe different depending on an interpretation of a field-A.

For example, when it is indicated that an SIB1-NB is transmitted on ananchor carrier in the field-A, a user equipment does not expect thefield-B or may interpret the field-B as information on the location of asubframe in which the SIB1-NB may be transmitted within the anchorcarrier.

When it is indicated that an SIB1-NB is transmitted on a non-anchorcarrier in the field-B, a user equipment may use the field-B to obtaininformation on a carrier on which an SIB1-NB is transmitted.

When an SIB1-NB is not transmitted on an anchor carrier, if a case wherethe SIB1-NB is “transmitted on only a non-anchor carrier” or a casewhere the SIB1-NB may be transmitted on both an “anchor-carrier andnon-anchor carrier” may be selected by an MIB-NB, the field-A may have asize of at least 2 bits.

The above-described SIB-NB transmission carrier location may bedifferent in each cell depending on a cell identifier (ID).

For example, a set of carriers on which an SIB1-NB may be transmittedmay be differently configured depending on the cell ID.

Furthermore, the interpretation of the location of a carrier on which anSIB1-NB may be transmitted may be defined to also include cell IDinformation along with information indicated in an MIB-NB.

If it is necessary to indicate the location k′ of a carrier on which anSIB1-NB is transmitted or the location of a subframe in which an SIB1-NBis transmitted using a different method within a non-anchor carrier setdepending on an operation mode, an MIB-NB may use the following methods.

Characteristically, the following methods are methods capable of usingsome statuses that are not used among 7 bits operationModeInfo withinthe MIB-NB.

(1) Use in-Band Different PCI Field

-   -   a carrier (on which an SIB1-NB is transmitted) may be indicated        using “eutra-CRS-SequenceInfo” 5 bits    -   when an SIB1-NB is transmitted on an anchor carrier, a subframe        #0, 8 or other subframe may be indicated using some bits of        “eutra-CRS-SequenceInfo”.

(2) Use Guardband Field

-   -   a carrier (on which an SIB1-NB is transmitted) may be indicated        using “eutra-CRS-SequenceInfo” 5 bits.    -   when an SIB1-NB is transmitted on an anchor carrier, a subframe        #0, 8 or other subframe may be indicated using some bits of        “eutra-CRS-SequenceInfo”.

(3) Use Standalone Field

-   -   a carrier (on which an SIB1-NB is transmitted) may be indicated        using “eutra-CRS-SequenceInfo” 5 bits.    -   when an SIB1-NB is transmitted on an anchor carrier, a subframe        #0, 8 or other subframe may be indicated using some bits of        “eutra-CRS-SequenceInfo”.

If an anchor-carrier is the guard band operation mode, the operationmode of a carrier on which an SIB1-NB may be transmitted may also belimited to the guard band operation mode.

This is for avoiding confusion in the information interpretation andapplication of an MIB-NB and an SIB1-NB between an anchor-carrier and anon-anchor carrier on which the SIB1-NB is transmitted.

In such a case, that is, if an operation mode is designated as aguard-band in an MIB-NB and an SIB1-NB carrier is designated as anon-anchor carrier, the SIB1-NB may be limited to be positioned in aguard-band on the side opposite to a guard-band including ananchor-carrier in an in-band system (LTE system).

This is different depending on the size of a guard-band. In general,this may be indirectly calculated based on the bandwidth of in-band LTE.

That is, when the bandwidth of an in-band LTE system is small, thenumber of (non-)anchor carriers capable of serving NB-IoT of a 180 kHzbandwidth in a left/right (or up/down) guard-band may be limited.

Accordingly, when a user equipment can be aware of the bandwidth of anin-band LTE system, the user equipment may easily calculate the locationof a carrier on the opposite side where an SIB1-NB is transmitted.

For example, when an anchor-carrier is a guard band operation mode andan SIB1-NB is transmitted on a non-anchor carrier, a user equipment maybe notified of a system bandwidth using unused bits or reserved bits orunused states of an MIB-NB. The user equipment may be aware of anon-anchor on which the SIB1-NB is transmitted on the opposite sidebased on the system bandwidth.

Furthermore, if the bandwidth of an in-band LTE system is wide, that is,in a guard-band widened compared to an in-band system bandwidth, anon-anchor carrier neighboring an anchor-carrier may be present evenwithin a guard-band on one side.

If such a case is considered, when an anchor-carrier is a guard bandoperation mode, the number of carriers on which an SIB1-NB may betransmitted may be 4.

That is, 1) an SIB1-NB may be transmitted on an anchor carrier, 2) anSIB1-NB may be transmitted on a left (or down) non-anchor carrierneighboring an anchor-carrier, 3) an SIB1-NB may be transmitted on aright (or up) non-anchor carrier neighboring an anchor-carrier, 4) anSIB1-NB may be transmitted on a non-anchor carrier symmetrical (ormeasurement relation location) to an anchor-carrier in a guard-band onthe side opposite to a guard-band to which the anchor-carrier belongs onthe basis of an in-band system.

In this case, the definition of the neighboring carrier or the symmetriccarrier on the opposite side means a logical relation. A physicalrelation (anchor-carrier and non-anchor carrier on which an SIB1-NB istransmitted) may be pre-defined or configured as a specific equation,etc. in 3GPP TS 36.xxx.

When an SIB1-NB is transmitted on a non-anchor carrier, a combination ofan anchor-carrier and the non-anchor carrier on which an SIB1-NB istransmitted may be the same as 1) to 3) below.

1) in-Band Anchor Carrier+in-Band Non-Anchor Carrier

-   -   Same PCI+same PCI    -   Different PCI+different PCI

2) Guard-Band Anchor Carrier+Guard-Band Non-Anchor Carrier (or in-BandNon-Anchor Carrier)

-   -   Guard-band (up/down)+guard-band (up/down)    -   Guard-band (up/down)+guard-band (down/up)    -   Guard-band (up/down)+inband same PCI    -   Guard-band (up/down)+inband different PCI

3) Standalone Anchor Carrier+Standalone Non-Anchor Carrier

In this case, in the case of the guard band operation mode, up and downmean an upper or lower frequency location in a frequency region based oneach inband.

Furthermore, in accordance with a table—arranged based on 3GPP TS36.104, if an inband bandwidth is 3 MHz or less, the guard bandoperation mode is not used.

Furthermore, if the guard band operation mode is used, it is recommendedthat the location of a carrier is used from a carrier closest to aninband.

Table 36 is a table showing an example of NB-IoT operation modes thatmay be permitted in system bands.

TABLE 36 System bandwidth 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHzN_(RB) 6 15 25 50 75 100 # NB IoT In-band N/A 9 19 44 69 94 carriersGuardband N/A N/A >0, but according to TS 36.104, it should be placedadjacent to the LTE PRB edge as close as possible Standalone N/A N/A N/AN/A N/A N/A

In order to determine a combination of the listed anchor-carrier andnon-anchor carrier used to transmit an SIB1-NB, there is a method usingunused or reserved bits of operationModeInfo-r13 7 bits of an MIB-NB.

Hereinafter, b1, b2, . . . , bN are represented in order to logicallydistinguish between unused or reserved bits in a bit unit when thenumber of unused or reserved bits is N.

b(n−1) and bn may not be contiguous, and b1 may not be the first or lastbit of unused or reserved bits. In this case, n is a natural numberbetween 1 to N.

1. Inband-SamePCI-r13

1) eutra-CRS-SequenceInfo-r13 {0 . . . 31}

2) reserved bits: 0

2. inband-Different PCI-r13

1) eutra-NumCRS-Ports-r13 {same, four}

2) fasterOffset-r13 {−7.5, −2.5, 2.5, 7.5}

3) Reserved bits: 2

The inband-Different PCI (physical cell ID) mode may be used to providenotification of whether an SIB1-NB is directly transmitted on an anchorcarrier or transmitted on a non-anchor carrier in a reserved bit.

That is, when an anchor-carrier is an inband-Different PCI mode, “11spare bits for future extension” of an MIB-NB may not be used torepresent information on a carrier on which an SIB1-NB is transmitted.

Furthermore, some bit(s) of 2 reserved bits may be used to providenotification of location information of a corresponding carrier when anSIB1-NB is transmitted on a non-anchor carrier.

As a simple embodiment, the location of a non-anchor carrier on which anSIB1-NB is transmitted may be used to determine {0, −2G, −G, +G} using 2bits based on an anchor-carrier.

In this case, G may be mapped as a PRB value or 180 kHz×G.

Furthermore, the value G be indicated using the remaining unused bit(s).

Furthermore, 0 may mean that an SIB1-NB is transmitted on ananchor-carrier.

3. guardband-r13

1) rasterOffset-r13 {−7.5, −2.5, 2.5, 7.5}

A user equipment may be aware whether an anchor-carrier is relatively alow frequency or a high frequency from an inband bandwidth based on therasteroffset-r13 information.

A user equipment may determine whether inband bandwidth information is(5 MHz or 15 MHz) or (10 MHz or 20 MHz).

That is, the user equipment cannot identify a value between 5 MHz and 15MHz and does not identify a value between 10 MHz and 20 MHz, but mayidentify at least two groups.

In this case, channel raster indicates a minimum unit by which the userequipment reads a resource. In the case of an LTE system, channel rasterhas a value of 100 kHz.

A user equipment sequentially monitors frequency values corresponding toa minimum frequency bandwidth (6RB, 1.08 MHz) as possible at channelraster (e.g., 100 kHz) intervals.

The channel raster offset may have four values of ±2.5 kHz (+2.5 kHz,−2.5 kHz) and ±7.5 kHz (+7.5 kHz, −7.5 kHz), for example.

The values may indicate a value obtained by subtracting an integermultiple of 100 kHz from the center frequency of a PRB based on 100 kHz(the center frequency of PRB—a multiple of 100 kHz).

2) Reserved Bits: 3

Unused 3 bits may be used to determine the operation mode of anon-anchor carrier on which an SIB1-NB is transmitted as follows.

Furthermore, some of the following cases may be omitted.

That is, the case of Guard-band (up/down)+inband same PCI may not bepresent.

{circle around (1)} b1

This value may be used to clearly determine bandwidth information of aninband not distinguished based on the above rasterOffset-r13.

{circle around (2)} {b2,b3}

In the above-described “combination of an anchor-carrier and anon-anchor carrier on which an SIB1-NB is transmitted”, when aguard-band is an anchor-carrier, 2 bits may be used as follows in orderto determine the operation mode of a non-anchor carrier on which anSIB1-NB is transmitted and the guard-band location of a non-anchorcarrier on which an SIB1-NB is transmitted (non-anchor carrier the sameside as the anchor-carrier or non-anchor carrier on the side opposite tothe anchor-carrier).

A. Guard-Band (Up/Down)+Guard-Band (Up/Down)

This indicates that a non-anchor carrier on the same side as ananchor-carrier is used for SIB1-NB transmission. For example,{b2,b3}={0,0}.

For example, when a non-anchor carrier on which an SIB1-NB istransmitted in the reserved bits of an MIB-NB has been indicated to be aneighbor high (or low) frequency compared to an anchor carrier, a userequipment may assume that a corresponding guard-band is indirectlylocationed in a frequency higher (or lower) than the frequency of an LTEsystem.

A non-anchor carrier on which an SIB1-NB is transmitted may becalculated to be 180 kHz higher (or lower) than an anchor carrierfrequency.

The reason for this is that there is an assumption that ananchor-carrier deployed in the guard-band primarily uses the closestfrequency in the LTE in-band.

B. Guard-Band (Up/Down)+Guard-Band (Down/Up)

This indicates that a non-anchor carrier on the side opposite to ananchor-carrier is used for SIB1-NB transmission.

For example, when an anchor-carrier is a high frequency (up) from anin-band, a non-anchor carrier on which an SIB1-NB is transmitted may bea low frequency (down) from the in-band. For example, {b2,b3}={0,1}.

For example, if a non-anchor carrier on which an SIB1-NB is transmittedhas been indicated to be a neighbor high (or low) frequency compared toan anchor carrier in the reserved bits of an MIB-NB, a user equipmentmay assume that a corresponding guard-band is indirectly positioned in alower (or higher) frequency than the frequency of an LTE system.

A non-anchor carrier on which an SIB1-NB is transmitted may becalculated to be higher (or lower) than an anchor carrier frequency bythe sum of the in-band bandwidth (assuming that it may be obtained bythe description) of an LTE system, 180 kHz, and an offset (it may be adifferent value depending on an LTE system bandwidth and may be a valueof 0 or 45 kHz, for example).

The reason for this is that there is an assumption that ananchor-carrier deployed in the guard-band primarily uses the closestfrequency in the LTE in-band.

C. Guard-Band (Up/Down)+Inband Same PCI

A non-anchor carrier on which an SIB1-NB is transmitted is present in anin-band and may indicate the same PCI mode. For example, {b2,b3}={1,0}.

In this case, in order to demodulate and decode the SIB1-NB, a userequipment needs to be aware of the number of NRS ports and an accuratelocation of a non-anchor carrier on which the SIB1-NB is transmitted.

First, the number of NRS ports may be assumed to be the same as a valueobtained from an anchor-carrier.

Furthermore, an accurate location of a non-anchor carrier on which anSIB1-NB is transmitted may be calculated based on in-band bandwidthinformation obtained by combining the above-described rasterOffset-r13and b1 and location information of a non-anchor carrier on which anSIB1-NB is transmitted within the in-band.

The corresponding information may be used as the same purpose asinformation transmitted through eutra-CRS-SequenceInfo-r13 in thein-band operation mode.

As a simple embodiment, when an in-band bandwidth obtained by combingrasterOffset-r13 and b1 is 20 MHz and an anchor-carrier is a lowfrequency (low frequency on the basis of a PRB index 0), the CRSlocation and sequence of a non-anchor carrier on which an SIB1-NB istransmitted may be precisely calculated when a PRB index 0 is obtained.

For example, if a non-anchor carrier on which an SIB1-NB is transmittedhas been indicated to be a neighbor high (or low) frequency compared toan anchor carrier in the reserved bits of an MIB-NB, a user equipmentmay assume that a corresponding guard-band is indirectly locationed in afrequency lower (or higher) than the frequency of an LTE system.

The user equipment may calculate the PRB index of the non-anchor carrieron which an SIB1-NB is transmitted as a value 0 (the greatest PRB indexsupported in an LTE system bandwidth).

The reason for this is that there is an assumption that ananchor-carrier deployed in the guard-band primarily uses the closestfrequency in the LTE in-band.

D. Guard-Band (Up/Down)+Inband Different PCI

A non-anchor carrier on which an SIB1-NB is transmitted is present in aninband, and may indicate a different PCI mode. For example,{b2,b3}={1,1}. In this case, in order to be precisely aware of SIB1-NBrate-matching information, it is necessary to be precisely aware of thenumber of CRS antenna ports of an inband.

As the simplest method, the number of CRS ports may be defined to bealways 4 or the number of NRS and CRS ports may be re-defined as aspecific combination.

For example, {the number of NRS ports, the number of CRS ports} may bedefined like {1, 2}, {2, 4} or {1, 4}, {2, 1}. In such a case, anaccurate number of CRS ports of an in-band may be indicated in anSIB1-NB.

For example, if a non-anchor carrier on which an SIB1-NB is transmittedhas been indicated to be a neighbor high (or low) frequency compared toan anchor carrier in the reserved bits of an MIB-NB, a user equipmentmay assume that a corresponding guard-band is indirectly positioned in afrequency lower (or higher) than the frequency of an LTE system.

The user equipment may calculate the PRB index of the non-anchor carrieron which an SIB1-NB is transmitted as a value 0 (the greatest PRB indexsupported in an LTE system bandwidth). The reason for this is that thereis an assumption that an anchor-carrier deployed in the guard-bandprimarily uses the closest frequency in the LTE in-band.

In the A to D, the case of C (Guard-band (up/down)+inband same PCI) isnot considered, both {1,0} and {1,1} of {b2,b3} are assumed to be aGuard-band (up/down)+inband different PCI combination, and {1,0} and{1,1} information may be used to represent the number of CRS ports.

This may be defined identically with eutra-NumCRS-Ports-r13 informationof Inband-Different PCI-NB-r13.

That is, the information of {1,0} and {1,1} of {b2,b3} may be used toindicate that the number of CRS ports of an inband non-anchor carrier onwhich an SIB1-NB is transmitted is the same as the number of NRS portsof an anchor-carrier or 4.

In the A to D, if an NB-IoT carrier is deployed in the guard-band, anoffset may be defined between an in-band edge and a guard-band dependingon an LTE system bandwidth.

For example, the offset value may be 45 kHz, which may be a differentvalue depending on the bandwidth.

In general, the corresponding value may be determined based on the RFrequirement of a base station/user equipment, such as TS36.104, etc.

The offset may be explicitly defined between the in-band edge and theguard-band depending on an LTE system bandwidth in 3GPP TS 36.xxx.

A user equipment may differently determine whether to apply the offsetvalue in interpreting he reserved bit.

For example, if an anchor-carrier is the guard band operation mode andan SIB1-NB is transmitted on a neighbor in-band non-anchor carrier, anactual location of the neighbor in-band non-anchor carrier may becalculated by applying the offset or not depending on an LTE systembandwidth.

Likewise, if an SIB1-NB is transmitted on a guard-band on the sideopposite to an anchor-carrier, a corresponding location may becalculated by applying an offset between a guard-band edge and anin-band edge or not depending on an LTE system bandwidth.

{circle around (3)} {b2,b3}—a method of using {b2,b3} if a case where anon-anchor carrier on which an SIB1-NB is transmitted is transmitted onan in-band on the side opposite to an anchor carrier based on an LTEcenter carrier (fc) is not supported is described.

If an SIB1-NB is transmitted on a non-anchor carrier and a relativelocation (higher/lower frequency based on an anchor-carrier, forexample,) of the corresponding non-anchor carrier is notified using thereserved bit(s) of an MIB-NB, a user equipment may be aware whether thecorresponding non-anchor carrier is a non-anchor carrier of aneighboring guardband or corresponds to the lowest/highest PRB locationof an LTE in-band neighboring the anchor-carrier.

That is, when an anchor carrier is positioned in a guardband, if theanchor carrier is permitted to include only a carrier closest to anin-band edge (in-band edge among guardband NB-IoT carriers permitted inthe in-band edge defined in the RAN4 standard or standard. This may bedefined as a value of 0 Hz or 45 kHz, etc. depending on an in-bandsystem bandwidth in 3GPP TS 36.xxx document) or if the anchor-carrier isthe guardband operation mode, if there is a condition that an SIB1-NBmust be closest to an LTE in-band edge at least in order to transmit theSIB1-NB on a non-anchor carrier, whether the corresponding non-anchorcarrier is the in-band operation mode may be aware based on onlyinformation (information obtained from the reserved bits of an MIB-NB)on the non-anchor carrier (on which the SIB1-NB is transmitted) from theanchor carrier.

The reason for this is that when an anchor carrier is positioned in theguard band, whether it is the guard band of a low frequency or the guardband of a high frequency from the center frequency of an LTE in-band canbe aware based on rasterOffset-r13.

In this case, when the non-anchor carrier on which an SIB1-NB istransmitted is positioned in the guardband, there is a problem in thatwhether the non-anchor carrier is positioned on the same side as theanchor-carrier (a relatively low or high frequency from the LTE centerfrequency) or positioned on the side opposite to the anchor-carrier isunaware.

In this case, when the non-anchor carrier is transmitted in theguardband on the side opposite to the anchor carrier, it is assumed thatonly a frequency symmetrical to the anchor-carrier based on the LTEcenter frequency is permitted.

One state of {b2,b3} may be used to determine location (the same side oropposite side) information of the above-described guardband.

For example, when an anchor-carrier is lower than an LTE centerfrequency (fc), when a relative frequency location of an SIB1-NBnon-anchor carrier obtained from an MIB-NB reserved bit is lower thanthat of an anchor carrier, it may be aware that the correspondingnon-anchor carrier is a guardband on the same side as the anchorcarrier.

When a non-anchor carrier on which an SIB1-NB is transmitted is higherthan that of an anchor carrier, it may be aware that the correspondingnon-anchor carrier is an LTE in-band edge (the lowest PRB index).

In the above-described case, if the relative frequency location of theSIB1-NB non-anchor carrier is assumed to be lower than that of theanchor carrier, when the state1 of {b2,b3} is indicated, it may beinterpreted that the corresponding non-anchor carrier is positioned in aguardband symmetric to LTE fc on the side opposite to the anchorcarrier.

Furthermore, the remaining state2, state3, state4 may be used todetermine an operation mode and the number of CRS ports when an SIB1-NBnon-anchor carrier obtained from an MIB-NB is positioned in the mostneighbor in-band PRB from an anchor carrier.

For example, the state2 may indicate that a corresponding non-anchorcarrier is an in-band samePCI mode.

In this case, the number of CRS ports may be assumed to be the same asthe number of NRS ports of an anchor-carrier.

The state3 and state4 may be used to additionally indicate the number ofCRS ports when a corresponding non-anchor carrier is an in-banddifferent PCI mode.

That is, when the state3 is indicated, it may be assumed that acorresponding non-anchor carrier is an in-band different PCI mode andthe number of CRS ports is the same as the number of NRS ports of ananchor-carrier.

When the state4 is indicated, a corresponding non-anchor carrier is anin-band different PCI mode and the number of CRS ports is 4.

4. standalone-r13

reserved bits: 5

In the case of the standalone mode, this may be used to providenotification whether an SIB1-NB is directly transmitted on ananchor-carrier or transmitted on a non-anchor carrier in the reservedbit of the standalone-r13 field.

That is, if an anchor-carrier is the standalone mode, the “11 spare bitsfor future extension” of an MIB-NB may not be used to representinformation on a carrier on which an SIB1-NB is transmitted.

Furthermore, some bit(s) of 5 reserved bits of the standalone-r13 fieldmay be used to provide notification of location information of acorresponding carrier if they correspond to a case where an SIB1-NB istransmitted on a non-anchor carrier.

As a simple embodiment, 2 bits of the 5 reserved bits of thestandalone-r13 field may be used to determine the location of anon-anchor carrier on which an SIB1-NB is transmitted based on ananchor-carrier {-2G, −G, +G, +2G}.

In this case, G may be mapped as a virtual PRB value or 180 kHz×G.

Furthermore, the value G may be indicated using the remaining unusedbit(s).

Furthermore, relative frequency location information of a non-anchorcarrier on which an SIB1-NB is transmitted from an anchor-carrier(information indicating whether the frequency location is higher orlower than the anchor carrier) is obtained through another signaling ofan MIB-NB. The relative offset size of the anchor-carrier and thenon-anchor carrier may be notified using some of corresponding reservedbits.

That is, in the example, when the location of a carrier used for SIB1-NBtransmission is obtained as −G or +G logical or absolute frequency unit(Hz) information from an anchor-carrier through another-bit informationof an MIB-NB, a detailed G value may be defined using some of thereserved 5 bits of the standalone-r13 field.

In this case, the G value may not be an integer.

For example, in the case of the standalone operation mode, a band thatmay be occupied by an NB-IoT carrier may be defined as 200 kHz not 180kHz in order to add an explicit guard-band (guard band for reducing aninterference influence between neighbor channels or carriers not theNB-IoT operation mode) to an NB-IoT standalone carrier.

In such a case, the relative frequency location of a non-anchor carrieron which an SIB1-NB is transmitted with respect to an anchor carrier mayneed to be defined as a 200 kHz unit not 180 kHz.

This value may be different depending on the carrier frequency (e.g.,EARFCN).

That is, a method of converting the relative frequency location of anon-anchor carrier on which an SIB1-NB is transmitted with respect to ananchor carrier into the center frequency value of an actual non-anchorcarrier may be different depending on the operation mode.

In particular, the standalone operation mode may be interpreted as anoffset unit having a different value (index) indicated in an MIB-NB.

If the above-described methods are used, when an anchor-carrier is theguard band operation mode as in FIG. 8 or 9, the location and operationmode of a non-anchor carrier on which an SIB1-NB may be transmitted maybe transmitted to a user equipment.

Furthermore, in the number of two cases of a combination of states notused in FIGS. 8 and 9, a non-anchor carrier on which an SIB1-NB istransmitted may be used to indicate a non-anchor carrier, notneighboring in an LTE in-band, as a carrier on which an SIB1-NB istransmitted in a guard-band on the side opposite to an anchor carrier.

FIG. 8 is a diagram showing an example of a method for interpretingsignaling information of an SIB1-NB non-anchor carrier in a MIB-NB whenan anchor carrier proposed in this specification is a guard bandoperation mode.

In drawings corresponding to the LTE in-bands of FIG. 8, a slashed partindicates an LTE bandwidth.

The LTE bandwidth may be obtained using 1 additional bit inrasterOffset-r13 in guardband-r13 and guardband-r13 of an MIB-NB.

In the drawing corresponding to Example 1 of FIG. 8, the first slashedpart on the left side of the LTE band means “when SIB1-NB non-anchorcarrier is indicated by 1 bit in MIB-NB as the lower PRB relative toanchor PRB and 2 spare bits in guardband-r13 is “0”.”

Furthermore, in the drawing corresponding to Example 1 of FIG. 8, thesecond slashed part on the left side of the LTE band means “anchorcarrier (its relative location to LTE in-band can be obtained by usingrasterOffset-r13 in guardband-r13 of MIB-NB).”

Furthermore, in the drawing corresponding to Example 1 of FIG. 8, thethird slashed part on the left side of the LTE band (i.e., the left part(PRB) of the LTE band means “when SIB1-NB non-anchor carrier isindicated by 1 bit in MIB-NB as the higher PRB relative to anchor PRBand 2 spare bits in guardband-r13 is ‘2’ (in-band different PCI) or ‘3’(in-band same PCI).”

Furthermore, in the drawing corresponding to Example 1 of FIG. 8, thefirst slashed part (PRB) on the right side of the LTE band means “whenSIB1-NB non-anchor carrier is indicated by 1 bit in MIB-NB as the higherPRB relative to anchor PRB and 2 spare bits in guardband-r13 is “1”.”

Furthermore, in a drawing corresponding to Example 2 of FIG. 8, thefirst slashed part on the left side of an LTE band means “when SIB1-NBnon-anchor carrier is indicated by 1 bit in MIB-NB as the lower PRBrelative to anchor PRB and 2 spare bits in guardband-r13 is “1”.”

Furthermore, in the drawing corresponding to Example 2 of FIG. 8, thefirst slashed part on the right side of the LTE band l (i.e., the rightpart (PRB) of the LTE band) means “when SIB1-NB non-anchor carrier isindicated by 1 bit in MIB-NB as the higher PRB relative to anchor PRBand 2 spare bits in guardband-r13 is ‘2’ (in-band different PCI) or ‘3’(in-band same PCI).”

Furthermore, in the drawing corresponding to Example 2 of FIG. 8, thesecond slashed part on the right side of the LTE band means “anchorcarrier (its relative location to LTE in-band can be obtained by usingrasterOffset-r13 in guardband-r13 of MIB-NB).”

Furthermore, in the drawing corresponding to Example 2 of FIG. 8, thethird slashed part (PRB) on the right side of the LTE band means “whenSIB1-NB non-anchor carrier is indicated by 1 bit in MIB-NB as the higherPRB relative to anchor PRB and 2 spare bits in guardband-r13 is “0”.”

All the PRBs corresponding to the slashed parts in Examples 1 and 2 ofFIG. 8 are non-anchor carriers used for SIB1-NB transmission.

FIG. 9 is a diagram showing another example of a method for interpretingsignaling information of an SIB1-NB non-anchor carrier in a MIB-NB whenan anchor carrier proposed in this specification is a guard bandoperation mode.

In drawings corresponding to LTE in-bands of FIG. 9, a slashed partindicates an LTE bandwidth.

The LTE bandwidth may be obtained using 1 additional bit inrasterOffset-r13 in guardband-r13 and guardband-r13 of an MIB-NB.

In the drawing corresponding to Example 1 of FIG. 9, the first slashedpart on the left side of the LTE band means “when SIB1-NB non-anchorcarrier is indicated by 1 bit in MIB-NB as the lower PRB relative toanchor PRB and 2 spare bits in guardband-r13 is “0”.”

Furthermore, in the drawing corresponding to Example 1 of FIG. 9, thesecond slashed part on the left side of the LTE band means an “anchorcarrier (its relative location to LTE in-band can be obtained by usingrasterOffset-r13 in guardband-r13 of MIB-NB).”

Furthermore, in the drawing corresponding to Example 1 of FIG. 9, thethird slashed part on the left side of the LTE band (i.e., the left part(PRB) of the LTE band) means “when SIB1-NB non-anchor carrier isindicated by 1 bit in MIB-NB as the higher PRB relative to anchor PRBand 2 spare bits in guardband-r13 is ‘2’ (in-band different PCI) or ‘3’(in-band same PCI).”

In the drawing corresponding to Example 1 of FIG. 9, the first slashedpart on the right side of the LTE band (i.e., the right part (PRB) ofthe LTE band) means “when SIB1-NB non-anchor carrier is indicated by 1bit in MIB-NB as the higher PRB relative to anchor PRB and 2 spare bitsin guardband-r13 is ‘2’ (in-band different PCI) or ‘3’ (in-band samePCI).”

Furthermore, in the drawing corresponding to Example 1 of FIG. 9, thesecond slashed part (PRB) on the right side of the LTE band means “whenSIB1-NB non-anchor carrier is indicated by 1 bit in MIB-NB as the higherPRB relative to anchor PRB and 2 spare bits in guardband-r13 is “1”.”

Furthermore, in the drawing corresponding to Example 2 of FIG. 9, thefirst slashed part on the left side of the LTE band means “when SIB1-NBnon-anchor carrier is indicated by 1 bit in MIB-NB as the lower PRBrelative to anchor PRB and 2 spare bits in guardband-r13 is “1”.”

Furthermore, in the drawing corresponding to Example 1 of FIG. 9, thesecond slashed part on the left side of the LTE band (i.e., the leftpart (PRB) of the LTE band) means “when SIB1-NB non-anchor carrier isindicated by 1 bit in MIB-NB as the higher PRB relative to anchor PRBand 2 spare bits in guardband-r13 is ‘2’ (in-band different PCI) or ‘3’(in-band same PCI).”

In the drawing corresponding to Example 2 of FIG. 9, the first slashedpart on the right side of the LTE band (i.e., the right part (PRB) ofthe LTE band) means “when SIB1-NB non-anchor carrier is indicated by 1bit in MIB-NB as the higher PRB relative to anchor PRB and 2 spare bitsin guardband-r13 is ‘2’ (in-band different PCI) or ‘3’ (in-band samePCI).”

Furthermore, in the drawing corresponding to Example 2 of FIG. 9, thesecond slashed part on the right side of the LTE band means “anchorcarrier (its relative location to LTE in-band can be obtained by usingrasterOffset-r13 in guardband-r13 of MIB-NB).”

Furthermore, in the drawing corresponding to Example 2 of FIG. 9, thethird slashed part (PRB) on the right side of the LTE band means “whenSIB1-NB non-anchor carrier is indicated by 1 bit in MIB-NB as the higherPRB relative to anchor PRB and 2 spare bits in guardband-r13 is “0”.”

All the PRBs corresponding to the slashed parts in Examples 1 and 2 ofFIG. 9 are non-anchor carriers used for SIB1-NB transmission.

Additional information for providing notification of information on acarrier on which an SIB1-NB is transmitted along with the proposedmethod may be indicated using some bit(s) of the “11 spare bits forfuture extension” of an MIB-NB.

This may be omitted when an anchor-carrier is inband-Different PCI orstandalone.

As a simple embodiment, the following methods may be used whencorresponding information is transmitted using 2 bits ({b1,b2}).

1) Bitmap Method

This may mean that when b1 is “0”, an SIB1-NB is transmitted on ananchor-carrier and if not (when b1 is “1”), an SIB1-NB is transmitted ona specific non-anchor carrier.

B2 is not used or may be disregarded when b1 is “0”.

Alternatively, when b1 is “0”, b2 may be used to indicate the locationof a subframe in which an SIB1-NB is transmitted on an anchor-carrier.

This may be limited to interpret b2 as information indicating thelocation of an SIB1-NB subframe only when an SIB1-NB repetition numberis 16.

When b2 is 0 and 1, this may mean that an each SIB1-NB is transmitted ata location having a −G or +G PRB (or −/+G×180 kHz) offset from ananchor-carrier.

In this case, G may be a value specified in 3GPP TS 36.xxx or a valuedifferent depending on a cell ID or SIB1-NB repetition number oroperation mode, etc.

In particular, when an anchor-carrier is a guardband operation mode andan SIB1-NB is transmitted on a non-anchor carrier, G may indicateinformation on whether an SIB1-NB is transmitted at a location having aspecific offset in a guardband on the same side as an anchor-carrier orwhether an SIB1-NB is transmitted at a location having a specific offsetin a guardband (the side opposite to an anchor-carrier) on the sideopposite to an anchor-carrier or whether an inband non-anchor carrier inwhich an SIB1-NB is transmitted has a specific offset based on thelowest PRB index or whether an inband non-anchor carrier on which anSIB1-NB is transmitted has a specific offset based on the highest PRBindex depending on {b1,b2,b3} of the guardband-r13.

In this case, a user equipment may differently determine whether G willbe interpreted as +/−G or interpreted as +G, +2G or interpreted as −G,−2G depending on a relative distance because it is aware of the relativedistance between a guardband anchor-carrier and an inband.

Furthermore, when an SIB1-NB is transmitted in an inband non-anchorcarrier, an offset is not specified based on the lowest or highest PRBindex, but an offset may be calculated based on a specific reference PRBindex.

As the most simple example, a PRB index closest to a PRB in which theprimary synchronization signal (PSS)/secondary synchronization signal(SSS) of an inband is transmitted may be a reference PRB index.

If the number of bits used for such a purpose is 3, b1 may be forproviding notification of whether an SIB1-NB is transmitted in ananchor-carrier. When an SIB1-NB is transmitted on a non-anchor carrier,b2 and b3 may be for providing notification of the location of thecorresponding carrier in more various manners.

2) Table Method

In order to transfer the same information as that of the above-describedBitmap method, {b1,b2} may be defined in a table, such as {0,0}, {0,1},{1,0}, {1,1}.

In this case, a method of omitting b2 based on a value of b1 cannot beapplied.

Position and Repetition Number of Subframe in which SIB1-NB May beTransmitted

Second, the location and repetition number of a subframe in which anSIB1-NB may be transmitted is described more specifically.

A carrier on which an SIB1-NB may be transmitted may be basicallydivided into three types as follows. The subframe location and/orrepetition number in which each SIB1-NB may be transmitted may bedifferent.

1. When an SIB1-NB is Transmitted on an Anchor Carrier

(1) When an SIB1-NB is Transmitted in a Fixed Subframe Index

The SIB1-NB may be transmitted in a subframe #0 in which a narrowbandsecondary synchronization signal (NSSS) is not transmitted.

In this case, the SIB1-NB may be transmitted based on a cell ID and anSIB1-NB repetition number like FIGS. 8 and 10.

Interference between cells may be avoided like the existing FDD withrespect to repetition numbers 4 and 8.

In contrast, if the repetition number is 16, an SIB1-NB may act asinterference between a cell having an odd number cell ID and a cellhaving an even-numbered cell ID.

Furthermore, the starting radio frame number of SIB1-NB transmission maybe configured like Table 37.

(2) When an SIB1-NB is Selectively Transmitted in One or More SubframeIndices

Information that determines a subframe index at which an SIB1-NB isactually transmitted among one or more subframe indices may be directlyindicated as specific information indicated in an MIB-NB (e.g., theremay be information that explicitly provides notification of the locationof a subframe index or a parameter associated with some information ofan UL/DL configuration along with the information (or solely) or may beconfigured so that subframe index information indicated in an MIB-NB isdifferently interpreted based on a cell ID.

Characteristically, an SIB1-NB may have a form in which it is alwaystransmitted in a subframe #0 in which an NSSS is not transmitted on ananchor-carrier and a subframe index indicated in an MIB-NB isadditionally transmitted in an indicated subframe.

A subframe index at which an SIB1-NB may be transmitted may be #0, 4, 8and 6. A subframe index at which an SIB1-NB is actually transmitted maybe selected (or indicated) using the above-described method.

A subframe index at which an SIB1-NB is actually transmitted may beassociated with information of an UL/DL configuration.

In this case, a user equipment may derive an SIB1-NB transmissionsubframe index from some of UL/DL configuration information provided inan MIB-NB or the user equipment may analogize some of UL/DLconfiguration information from an SIB1-NB transmission subframe indexindicated in an MIB-NB.

For example, in an UL/DL configuration #1, an SIB1-NB may be transmittedin a subframe #0 or #4 only. In UL/DL configurations #2 to #5, anSIB1-NB may be transmitted in a subframe #0 or #8 (or #6 not #8) only.

If an UL/DL configuration #6 is supported, an SIB1-NB may be transmittedonly in a subframe #0 in which an NSSS is not transmitted. A repetitionnumber 16 may not be supported.

Furthermore, the starting radio frame number of SIB1-NB transmission maybe configured like Table 37.

If some of UL/DL configuration information is indicated within an MIB-NBand the number of subframe indices in which an SIB1-NB may betransmitted from some information of an UL/DL configuration that may beaware by a user equipment from corresponding information is greater thanone, a subframe index at which an SIB1-NB is actually transmitted in maybe selected as cell ID a corresponding cell.

As a simple example, when an SIB1-NB is transmitted in one of twosubframe indices based on a cell ID, a subframe index may be determineddepending on whether “((cell_ID-(cell_ID % NRep))/NRep) % 2” is 0 or 1.

If an SIB1-NB transmitted in an anchor-carrier may be transmitted in asubframe #0 or subframe #4 and a subframe index may be indicated in anMIB-NB, a starting radio frame number/index at which an SIB1-NBrepetition starts within 2560 msec may be defined like Table 38.

Furthermore, this may be limited to only a case where the SIB1-NBrepetition number is 16.

That is, a user equipment may obtain information indicating that anSIB1-NB is transmitted in the place (e.g., subframe #4) not the subframe#0 through the MIB-NB, and may be then aware of a radio frame index atwhich the SIB1-NB transmission starts based on the cell ID of acorresponding cell.

In contrast, if information indicating that an SIB1-NB is transmitted ina subframe #0 is obtained through the MIB-NB and an SIB1-NB repetitionnumber is 16, SIB1-NB transmission may be assumed to always start from aNo. 1 radio frame number within 2560 msec regardless of a cell ID as inTable 37.

In other words, when an SIB1-NB is transmitted on an anchor-carrier anda repetition number is 16, a radio frame index at which SIB1-NBtransmission starts may be differently interpreted depending on whethera subframe index at which the SIB1-NB is transmitted is #0 or #4.

As a corresponding example, Table 37 (when an SIB1-NB is transmitted ina subframe #0) and Table 38 (when an SIB1-NB is transmitted in asubframe #4) may be taken into consideration.

2. When an SIB1-NB is Transmitted on a Non-Anchor Carrier Only

The number of subframes used for SIB1-NB transmission in a specificsection may be N times greater than a value when an SIB1-NB istransmitted on an anchor-carrier.

The reason for this is that power boosting of a non-anchor carrier maybe difficult to apply compared to an anchor-carrier.

N may be determined by downlink transmit power of an anchor-carrier anddownlink transmit power of a non-anchor carrier on which an SIB1-NB istransmitted.

If the relation between downlink transmit power of a carrier on which anSIB1-NB is transmitted and downlink transmit power of an anchor-carrieris notified in an MIB-NB, N may be derived or analogized fromcorresponding information.

Alternatively, in contrast, the N value may be notified in an MIB-NB,and the relation between downlink transmit power of a carrier on whichan SIB1-NB is transmitted and downlink transmit power of ananchor-carrier may be derived (or analogized).

In this case, “the number of subframes used for SIB1-NB transmissionwithin a specific section” is value or concept corresponding to an“SIB1-NB repetition number.” The “SIB1-NB repetition number” indicatesthe number of an SIB1-NB transmission time interval (TTI) number usedfor SIB1-NB transmission by a specific cell within an SIB1-NBmodification period.

“The number of subframes used for SIB1-NB transmission within a specificsection” indicates the number of subframes used for SIB1-NB transmissionwithin a specific absolute time interval (e.g., 160 msec or 40.96 sec).

N of subframe indices #0, #5, #9 may be selected as a subframe index atwhich an SIB1-NB may be transmitted and used.

For example, in the case of N2, the subframe indices #0 and 9 may beused. In the subframe indices #0 and #9, radio frame numbers may beselected as an odd number and an even number, respectively, in order tocontiguously transmit the SIB1-NB.

In this case, if system frame number (SFN) information of the SIB1-NBtransmitted in different radio frames is different and correspondinginformation is included in some of the SFN information of SIB1-NBcontents, the SFN of a radio frame in which a specific first or lastSIB1-NB starts to be transmitted may be a basis.

Alternatively, subframe indices #0 and #5 not used as a multimediabroadcast multicast service single frequency network (MBSFN) subframemay be used.

The N2 means a case where an SIB1-NB repetition number indicated withinan MIB-NB is interpreted as being a twice-times greater value when anSIB1-NB is transmitted on a non-anchor carrier.

That is, the SIB1-NB repetition number indicated within an MIB-NB is therepetition number of an SIB1-NB when an SIB1-NB is transmitted on ananchor carrier.

If an SIB1-NB is transmitted on a non-anchor carrier, the repetitionnumber of the SIB1-NB indicated in an MIB-NB may be differentlyinterpreted.

Likewise, in the case of N4, corresponding information is interpreted asbeing four times greater. Such a series of procedure and interpretationmay be different depending on whether the location of a carrier on whichan SIB1-NB is transmitted is an anchor-carrier or a non-anchor carrier,how far is an SIB1-NB relatively positioned from an anchor-carrier whenit is transmitted on a non-anchor carrier (e.g., whether it is a PRBinterval smaller than X) or an operation mode.

In this case, the operation mode may be the operation mode of ananchor-carrier, may be the operation mode of a non-anchor carrier inwhich the SIB1-NB is transmitted, or may be a combination of theoperation modes of an anchor-carrier and a non-anchor carrier in whichthe SIB1-NB is transmitted.

As a simple example, it may be N2 (N=2) when a non-anchor carrier onwhich an SIB1-NB is transmitted is an inband operation mode, and may beN4 (N=4) when a non-anchor carrier on which an SIB1-NB is transmitted isa guardband operation mode.

In this case, in the case of N4, a subframe index at which the SIB1-NBmay be transmitted may be a subframe #0, #4, #5, #9.

In the case of the N2 and N4, the number of subframes used to transmitan SIB1-NB transport block (TB) once needs to be maintained to 8. AnSIB1-NB transmission period needs to be fixed to 2560 msec.

To this end, the number of radio frames used to transmit an SIB1-NB maybe different.

That is, the number of subframes used for SIB1-NB transmission withinone radio frame may be 2 (in the case of N2) or 4 (in the case of N4).

In the case of N2, characteristically, neighbor subframes used forSIB1-NB transmission may be present in different radio frames.

If the number of subframes used for SIB1-NB transmission within a radioframe is different as described above, the starting index of the radioframe used for SIB1-NB transmission may be differently defined.

As a simple example, a radio frame number (nf mod 256) value for theNB-SIB1 repetitions of Table 38 may be different.

In the case of N2, it is simply given as (start radio frame number valueof Table 37 defined based on an SIB1-NB repetition number and a cellID−1)/2 or (start radio frame number value of Table 37 defined based onan SIB1-NB repetition number and a cell ID−1)/2+1, and an SIB1-NBtransmission window may be defined as 80 msec.

As a similar method, in the case of N4, it is simply given as (startradio frame number value of Table 38 defined based on an SIB1-NBrepetition number and a cell ID−1)/4 or (start radio frame number valueof Table 38 defined based on an SIB1-NB repetition number and a cellID−1)/4+1. An SIB1-NB transmission window may be defined as 40 msec.

Although an SIB1-NB is transmitted on a non-anchor carrier, if anSIB1-NB repetition number is the same as that of an anchor-carrier, thesame start radio frame number as that of Table 38 may be used or thestart radio frame number value of Table 38-1 may be defined.

The above contents may be represented like Table 39, Table 40 and Table41 in a table form.

In each table, the number of NPDSCH repetitions is the repetition numberof an SIB1-NB transmitted on a non-anchor carrier. This is a valuederived from the SIB1-NB repetition number of an MIB-NB.

If an SIB1-NB is transmitted in N subframes within one radio frame, inthe SIB1-NB transmitted in the N-times subframes, as in FIG. 10, theremay be (1) a method of sequentially transmitting A to H sub-blocks and(2) a method of contiguously transmitting each sub-block in a subframe Ntimes (or value greater than 1) and contiguously transmitting a nextsub-block N times.

In this case, the A to H sub-blocks indicate a unit in which thesub-block is transmitted in one subframe at the circular-buffer outputof an SIB1-NB codeword.

If a specific sub-block is repeatedly transmitted as in the method of(2), there may be a disadvantage in that inter-cell interference occurs.

Accordingly, although sub-blocks are transmitted within the same radioframe, scrambling needs to be differently applied.

For example, in the current scrambling equationc_(min)=n_(RND)·2¹⁵+(N_(ID) ^(Ncell)+1)((n_(f) mod 61)+1), whensub-blocks are repeatedly transmitted within the same radio frame,scrambling between the sub-blocks may be modified to be differentlyapplied although a radio frame number and nRNTI, N_(ID) ^(cell), nf arethe same.

For example, scrambling may be defined as a different cinit having aspecific offset between subframes.

Alternatively, scrambling may be performed in a form phase-rotated in anI/Q-level for each RE between sub-blocks (subframes) repeatedlytransmitted within the same radio frame.

This may be similar to or identical with a method of applying thephase-rotation of an I/Q-level in an NPBCH (e.g., the first equation in10.2.4.4 of TS.36.211).

$\begin{matrix}{{\theta_{f}(i)} = \{ \begin{matrix}{1,{{{if}\mspace{14mu} {c_{f}( {2i} )}} = {{0\mspace{14mu} {and}\mspace{14mu} {c_{f}( {{2i} + 1} )}} = 0}}} \\{{- 1},{{{if}\mspace{14mu} {c_{f}( {2i} )}} = {{0\mspace{14mu} {and}\mspace{14mu} {c_{f}( {{2i} + 1} )}} = 1}}} \\{j,\; {{{if}\mspace{14mu} {c_{f}( {2i} )}} = {{1\mspace{14mu} {and}\mspace{14mu} {c_{f}( {{2i} + 1} )}} = 0}}} \\{{- j},\; {{{if}\mspace{14mu} {c_{f}( {2i} )}} = {{1\mspace{14mu} {and}\mspace{14mu} {c_{f}( {{2i} + 1} )}} = 1}}}\end{matrix} } & \lbrack {{Equation}\mspace{14mu} 21} \rbrack\end{matrix}$

A scrambling sequence c_(f)(j), j=0, . . . , 199 is given in 7.2 of TS36.211.

3. When an SIB1-NB is Transmitted on Both an Anchor-Carrier and aNon-Anchor Carrier

A subframe index at which SIB1-NB is transmitted may be configured tonot overlap between an anchor-carrier and a non-anchor carrier.

Alternatively, although subframe indices are the same, actuallytransmitted radio frames may be configured to be different.

This may be for providing a user equipment with a change to improveperformance by receiving both SIB1-NBs transmitted on an anchor-carrierand a non-anchor carrier.

The “1. when an SIB1-NB is transmitted on an anchor carrier only” andthe “2. when an SIB1-NB is transmitted on a non-anchor carrier only” maybe extended and applied with respect to each anchor-carrier andnon-anchor carrier.

FIG. 10 is a diagram showing an example of the transmission location ofan SIB1-NB proposed in this specification.

In this case, a drawing corresponding to FIG. 10 is large and thusdivided into FIGS. 10a, 10b and 10c , and FIGS. 10a, 10b and 10c aredrawings completing the one drawing.

FIGS. 11 and 12 show examples of the transmission location of an SIB1-NBaccording to a repetition number proposed in this specification.

Specifically, FIG. 11 is a diagram showing an example of thetransmission location of an SIB1-NB when the repetition number is 4, andFIG. 12 is a diagram showing an example of transmission location of anSIB1-NB when the repetition number is 8.

Table 37 is a table showing the location of a starting radio frame forthe first transmission of an NPDSCH on which an SIB1-NB is carried.

TABLE 37 Number of Starting radio frame number NPDSCH for NB-SIB1repetitions repetitions N_(ID) ^(Ncell) (nf mod 256)  4 N_(ID) ^(Ncell)mod 4 = 0  1 N_(ID) ^(Ncell) mod 4 = 1 17 N_(ID) ^(Ncell) mod 4 = 2 33N_(ID) ^(Ncell) mod 4 = 3 49  8 N_(ID) ^(Ncell) mod 2 = 0  1 N_(ID)^(Ncell) mod 2 = 1 17 16 N_(ID) ^(Ncell) mod 2 = 0  1 N_(ID) ^(Ncell)mod 2 = 1  1

Table 38 is a table showing an example of a starting radio frame for thefirst transmission of an NPDSCH on which an SIB1-NB is carried.

TABLE 38 Starting radio frame Number of NPDSCH number for NB-repetitions N_(ID) ^(Ncell) SIB1 repetitions (nf mod 256)  4 N_(ID)^(Ncell) mod 4 = 0  1 N_(ID) ^(Ncell) mod 4 = 1 17 N_(ID) ^(Ncell) mod 4= 2 33 N_(ID) ^(Ncell) mod 4 = 3 49  8 N_(ID) ^(Ncell) mod 2 = 0  1N_(ID) ^(Ncell) mod 2 = 1 17 16 N_(ID) ^(Ncell) mod 2 = 0 0 (or 1)N_(ID) ^(Ncell) mod 2 = 1 1 (or 0)

Table 39 is a table showing an example of a starting radio frame for thefirst transmission of an NPDSCH on which an SIB1-NB is carried.

TABLE 39 Starting radio frame Number of NPDSCH number for NB-repetitions N_(ID) ^(Ncell) SIB1 repetitions (nf mod 256)  4 N_(ID)^(Ncell) mod 4 = 0 1 (or 0) N_(ID) ^(Ncell) mod 4 = 1 17 (or 16) N_(ID)^(Ncell) mod 4 = 2 33 (or 32) N_(ID) ^(Ncell) mod 4 = 3 49 (or 48)  8N_(ID) ^(Ncell) mod 2 = 0 1 (or 0) N_(ID) ^(Ncell) mod 2 = 1 17 (or 16)16 N_(ID) ^(Ncell) mod 2 = 0 0 (or 1) N_(ID) ^(Ncell) mod 2 = 1 1 (or 0)

Table 40 is a table showing another example of a start radio frame forthe first transmission of an NPDSCH on which an SIB1-NB is carried.

TABLE 40 Starting radio frame Number of NPDSCH number for NB-repetitions N_(ID) ^(Ncell) SIB1 repetitions (nf mod 128)  8 N_(ID)^(Ncell) mod 4 = 0 1 (or 0) N_(ID) ^(Ncell) mod 4 = 1 9 (or 8) N_(ID)^(Ncell) mod 4 = 2 17 (or 16) N_(ID) ^(Ncell) mod 4 = 3 25 (or 24) 16N_(ID) ^(Ncell) mod 2 = 0 1 (or 0) N_(ID) ^(Ncell) mod 2 = 1 9 (or 8) 32N_(ID) ^(Ncell) mod 2 = 0 o (or 1)

Table 41 is a table showing another example of a start radio frame forthe first transmission of an NPDSCH on which an SIB1-NB is carried.

TABLE 41 Number of NPDSCH Starting radio frame number for NB-SIB1repetitions N_(ID) ^(Ncell) repetitions (nf mod 64) 16 N_(ID) ^(Ncell)mod 4 = 0 1 (or 0) N_(ID) ^(Ncell) mod 4 = 1 5 (or 4) N_(ID) ^(Ncell)mod 4 = 2 9 (or 8) N_(ID) ^(Ncell) mod 4 = 3 13 (or 12) 32 N_(ID)^(Ncell) mod 2 = 0 1 (or 0) N_(ID) ^(Ncell) mod 2 = 1 5 (or 4) 64 N_(ID)^(Ncell) mod 2 = 0 0 (or 1)

FIG. 13 is a diagram showing an example of the codeword and resourcemapping of an SIB1-NB proposed in this specification.

The location and repetition number of a subframe and/or radio frame inwhich an SIB1-NB is transmitted may be differently interpreted dependingon an operation mode of a carrier on which an SIB1-NB is transmitted.

That is, the location of a subframe and/or radio frame in which anSIB1-NB is transmitted may be different depending on a cell ID andrepetition number.

This is provided in an MIB-NB, but may be differently interpreted whenan SIB1-NB is transmitted on a non-anchor carrier.

Furthermore, a repetition number indicated in an MIB-NB may bedifferently interpreted depending on the operation mode of a non-anchorcarrier on which an SIB1-NB is transmitted (e.g., a value two timesgreater than a repetition number indicated by an MIB-NB).

The location of a subframe and/or radio frame in which an SIB1-NB istransmitted may be differently interpreted for each operation mode.

In this case, “for each operation mode” includes the operation mode ofan anchor-carrier and the operation mode of a non-anchor carrier onwhich an SIB1-NB is actually transmitted.

For example, when an anchor carrier is an in-band operation mode, but anSIB1-NB is transmitted on the same carrier, the repetition number isinterpreted as one value of {4, 8, 16}.

However, when an SIB1-NB is transmitted on a non-anchor carrier and thecorresponding non-anchor carrier is the in-band operation modem, therepetition number may be interpreted as one value of {8, 16, 32}.

Furthermore, when an SIB1-NB is transmitted on a non-anchor carrier andthe corresponding non-anchor carrier is the guard band operation mode,the repetition number may be interpreted as one value of {2, 4, 8}.

Subframe in which an NRS Cannot be Expected without System Information

Third, the location of a subframe in which an NRS cannot be alwaysexpected without system information is described.

In order to improve demodulation performance of a signal received in aspecific subframe, there is a need for cross-subframe channel estimationfor estimating a channel using a subframe in which the correspondingsignal is received and an NRS included in a preceding and/or followingsubframe.

In particular, when a user equipment receives an MIB-NB and an SIB1-NBwithout system information, there may be a need for a subframedefinition in which an NRS can always be expected even in a subframe nota subframe in which the MIB-NB and the SIB1-NB are transmitted.

The location of a subframe in which an NRS can always be expected asdescribed above is referred to as a “default subframe.”

This may be different from downlinkBitmap information configured as anSIB1-NB or other SIBx-NB, or RRC.

First, a default subframe that may be assumed by a user equipment beforeit detects an MIB-NB may be a subframe #0 and subframe #9 in which theNSSS of an anchor-carrier is not transmitted.

This may not have a relation with whether an SIB1-NB is actuallytransmitted on an anchor carrier.

A default subframe that may be assumed by a user equipment before itdetects an SIB1-NB after an MIB-NB is detected may be divided as followsand differently determined.

1. When an SIB1-NB is Transmitted on an Anchor Carrier

In this case, a default subframe that may be assumed by a user equipmentmay be a subframe #0 and subframe #9 in which the NSSS of ananchor-carrier is not transmitted, like a default subframe that may beassumed by a user equipment before it detects an MIB-NB.

If some information corresponding to an UL/DL configuration cannot beadditionally obtained from an MIB-NB, some subframe may be additionallyincluded as a default subframe characteristically in the correspondingUL/DL configuration.

For example, some subframe may be one of subframes #4, #6 and #8.

This may be derived from some information of an UL/DL configuration asdescribed above.

Alternatively, some subframe may be explicitly notified in an MIB-NB.

In this case, a user equipment may assume a default subframe only withinan SIB1-NB TTI and/or an SIB1-NB transmission window (160 msec) and/or aradio frame in which a corresponding cell is expected to transmit anSIB-NB.

Alternatively, the corresponding subframe may be explicitly notifieddirectly within an MIB-NB.

Furthermore, the user equipment may expand some section a little aheadof/behind a limited specific section which may include theabove-described default subframe, and may expect the default subframe.

A subframe in which a user equipment may expect an NRS in ananchor-carrier may be divided into several steps based on informationobtained by a user equipment as follows.

1) Before a User Equipment Obtains operationModeInfo

A subframe in which a user equipment may expect NRS reception before itcompletes NPBCH detection although it has detected a TDD NB-IoT cell isa subframe #9 and a subframe #0 in which an NSSS is not transmitted.

If an NRS may be always transmitted in a specific pattern (e.g., whenthe NRS is transmitted in a third OFDM symbol) regardless of the numberof DwTS symbols in the downlink pilot time slot (DwPTS) of a subframe#1, a user equipment may expect an NRS even in the DwPTS section of thecorresponding subframe.

As a similar method, if an NRS may be always transmitted in a specificpattern regardless of an UL/DL configuration and a special subframeconfiguration even in a subframe #6, a user equipment may expect an NRSin some OFDM symbols even in the corresponding subframe. This is appliedregardless of a carrier on which an SIB1-NB is transmitted.

2) Before a User Equipment Obtains an SIB1-NB after it ObtainsoperationModeInfo

As a method of notifying a user equipment of a subframe in which an NRSmay be expected even in a subframe not subframes listed below beforeSIB1-NB information is obtained, the unused state(s) or unused bit(s) ofan MIB-NB may be used.

A. When operationModeInfo Indicates an Inband

{circle around (1)} when an SIB1-NB is Present in a Subframe #0

An NRS may be expected in the subframe defined in the 1). The same istrue of a case where an SIB1-NB is transmitted on a non-anchor carrier.

{circle around (2)} IN ADDITION, WHEN AN SIB1-NB IS PRESENT IN ASUBFRAME #4

An NRS may be expected in the subframe defined in the 1). Additionally,an NRS may be expected even in the subframe #4.

The same is true of a case where an SIB1-NB is transmitted on anon-anchor carrier.

In this case, an NRS may be limited to be expected in the subframes #4of all radio frames, an NRS may be limited to be expected in thesubframe #4 of a radio frame in which an SiB12-NB is actuallytransmitted, an NRS may be limited to be expected only in the subframe#4 of a radio frame between former N radio frames of a radio frame inwhich an SiB12-NB is actually transmitted and the latter M radio framesof the radio frame in which the SiB12-NB is actually transmitted or anNRS may be limited to be expected only in the subframe #4 of a windowsection (160 msec, for example, in an anchor-carrier) in which anSIB1-NB TTS is divided into 8 subframes and transmitted. In this case, Nand M are natural numbers.

When an SIB1-NB is transmitted in a subframe #4, it may be transmittedin an even-numbered radio frame or odd-numbered radio frame number basedon a cell ID, as in Table 10 and FIG. 13.

This is possible only when an SIB1-NB repetition number is 16.

An example of A-1 and A-2 may be checked based on the location of asubframe including R in FIG. 14.

B. In Addition, when operationModeInfo Indicates a Guardband

In the inband operation mode of the A., a user equipment may expect anNRS using the same method at the location of a subframe in which the NRSmay be expected.

In the case of the guardband operation mode, if a base station canalways transmit an NRS in a specific OFDM symbol(s) in a control regionwithin a DwPTS, a user equipment may expect an NRS in the correspondingOFDM symbol(s) even in the DwPTS of a subframe #1 in addition to thesubframe of the A.

This may be identically applied to the standalone operation mode, butthe location of an OFDM symbol(s) in which an NRS may be expected in theDwPTS may be different between the guardband and standalone operationmodes.

If the location of a subframe in which an NRS may be transmitted withina DwPTS depending on the number of OFDM symbols within the DwPTS, thelocation of an OFDM symbol in which the NRS may be expected within thecorresponding DwPTS may be indicated using some reserved or unusedbit(s) within an MIB-NB.

In this case, some or all of 3 bits except rasterOffset-r13 of 2 bits inguardband-r13 of 5 bits may be used as an example of the unused bit(s).

Furthermore, the corresponding information may be differentlyinterpreted and indicated when an SIB1-NB is transmitted on an anchorcarrier and when an SIB1-NB is transmitted on a non-anchor carrier ordepending on the number of unused bits used in the location of asubframe in which an SIB1-NB is transmitted or a different method (e.g.,different table).

C. In Addition, when operationModeInfo is Indicated as Standalone

In the inband operation mode of the A., an NRS may be expected using thesame method in the location of a subframe in which a user equipment mayexpect the NRS.

In the case of the standalone operation mode, if a base station canalways transmit an NRS in a specific OFDM symbol(s) in a control regionwithin a DwPTS, a user equipment may expect an NRS the correspondingOFDM symbol(s) even in the DwPTS of a subframe #1 in addition to thesubframe of the A.

If the location of a subframe in which an NRS may be transmitted withina DwPTS may be different depending on the number of OFDM symbols withinthe DwPTS, the location of an OFDM symbol in which the NRS may beexpected within the corresponding DwPTS may be indicated using somereserved or unused bit(s) within an MIB-NB.

In this case, some or all of 5 bits in the standalone-r13 field of 5bits may be used as an example of an unused bit(s).

For example, the standalone operation mode may include a case where aDwPTS is not used in a special subframe. Accordingly, a case foridentifying the example may be included, and some of unused bits may beused.

Furthermore, the unused bits may be used to indicate some of UL/DLconfiguration (including the UL/DL configuration of the existing LTE andan UL/DL configuration added in the TDD LTE standalone mode) informationin the standalone mode.

That is, although an UL/DL configuration has not been clearly indicated,if there is a subframe in which an NRS may be additionally expecteddepending on the UL/DL configuration, some information of the UL/DLconfiguration may be indicated using unused bits in order to identifythe subframe.

Furthermore, the corresponding information may be differentlyinterpreted and indicated when an SIB1-NB is transmitted on an anchorcarrier and when an SIB1-NB is transmitted on a non-anchor carrier ordepending on the number of unused bits used in the location of asubframe in which an SIB1-NB is transmitted or a different method (e.g.,different table).

FIG. 14 is a diagram showing an example of the location of a subframe inwhich an NPSS/NSSS/NPBCH/SIB1-NB is transmitted on an anchor-carrierproposed in this specification.

FIG. 15 is a diagram showing another example of the location of asubframe in which an NPSS/NSSS/NPBCH/SIB1-NB/NRS is transmitted on ananchor carrier proposed in this specification.

In this case, the drawing corresponding to FIG. 15 is large and thusdivided into FIGS. 15a, 15b, 15c and 15d . FIGS. 15a, 15b, 15c and 15dare drawings completing the one drawing.

2. When an SIB1-NB is Transmitted on a Non-Anchor Carrier

In this case, a default subframe that may be assumed by a user equipmentmay be indicated in an MIB-NB or may be all the subframes #0, #5, #9 ofa carrier on which an SIB1-NB derived based on the indication of anMIB-NB, a cell ID, etc. is transmitted or may be #0 and #5.

Furthermore, the default subframe may be dependently determined by thelocation of a subframe in which an SIB1-NB is transmitted.

The default subframe may be the subframes #0, #5 and #9 included in somesection in a time before and after the subframe in which an SIB1-NB istransmitted, including the subframe in which an SIB1-NB is transmitted.

Furthermore, a user equipment may assume a default subframe only withinan SIB1-NB TTI and/or an SIB1-NB transmission window (160 msec) and/or aradio frame in which a corresponding cell expects to transmit an SIB-NB.

Alternatively, a default subframe may be explicitly notified in anMIB-NB.

Furthermore, a user equipment may expand some section a little aheadof/behind a limited specific section that may include theabove-described default subframe, and may expect the default subframe.

Furthermore, if some information corresponding to an UL/DL configurationmay be additionally obtained in an MIB-NB, some subframes may beadditionally included in the default subframe characteristically in thecorresponding UL/DL configuration.

For example, some subframe may be one of subframes #4, #6 and #8.

As described above, some subframe may be derived from some informationof an UL/DL configuration or may be explicitly notified directly in anMIB-NB. A subframe in which a user equipment may expect an NRS on anon-anchor carrier on a non-anchor carrier on which an SIB1-NB istransmitted is as follows.

In this case, since the location of the carrier on which the SIB1-NB istransmitted is indicated in an MIB-NB, it is assumed that the userequipment has obtained information on the location of the carrier onwhich the SIB1-NB is transmitted, the number of SIB1-NB repetitions, thelocation of a radio frame in which the SIB1-NB is transmitted, thelocation of a subframe in which the SIB1-NB is transmitted, along withall types of information on the MIB-NB.

1) after a User Equipment Obtains operationModeInfo and Before the UserEquipment Obtains an SIB1-NB

When an SIB1-NB is transmitted on a non-anchor carrier, the location ofa subframe and radio frame used for SIB1-NB transmission may bedifferent depending on the number of SIB1-NB repetitions.

It is evident that a user equipment can expect an NRS in a subframe usedfor SIB1-NB transmission on a non-anchor carrier because information onthe location is obtained from an MIB-NB.

Furthermore, an NRS may be expected regardless of the location of aradio frame and subframe in which an SIB1-NB is transmitted in subframes#5, #0 and #9 used for NPSS, NSSS and MIB transmission on an anchorcarrier.

Furthermore, in the case of the standalone operation mode, a userequipment may additionally expect an NRS even in subframes #4 and #8.

Furthermore, a user equipment may expect an NRS in a DwPTS section. Inthis case, the above-described method (method of expecting an NRS in theDwPTS section when an SIB1-NB is transmitted on an anchor-carrier) maybe identically used with respect to a case regarding whether an NRS maybe expected depending on an operation mode or a case where an NRS may beexpected in which OFDM symbol within a DwPTS.

The above-described subframe in which an NRS may be expected may beidentically applied for each radio frame, or may be limited to onesubframe belonging to a radio frame in which an SIB1-NB is transmitted,or may be limited so that an NRS can be expected only within a radioframe between former N radio frames of a radio frame in which anSiB12-NB is actually transmitted and latter M radio frames of a radioframe in which an SiB12-NB is actually transmitted, or may be limited sothat an NRS can be expected only in the subframe of a window section(160 msec, in an anchor-carrier, for example) in which an SIB1-NB TTS isdivided into 8 subframes and transmitted.

This may be differently applied depending on a subframe number in whichan NRS may be expected and an operation mode. In this case, N and M arenatural numbers.

3. When an SIB1-NB is Transmitted on Both an Anchor-Carrier and aNon-Anchor Carrier

In this case, a default subframe may follow the (1) method on an anchorcarrier that may be assumed by a user equipment, and a default subframemay follow the (2) method on a non-anchor carrier on which an SIB1-NB istransmitted.

In this case, when an SIB1-NB is not transmitted on an anchor carrier,if both a “case where an SIB1-NB is transmitted on a non-anchor carrier”and a “case where an SIB1-NB is transmitted on both an anchor-carrierand a non-anchor carrier” can be configured in an MIB-NB, a defaultsubframe that may be expected by a user equipment on a non-anchorcarrier on which an SIB1-NB is transmitted may be different between the“case where an SIB1-NB is transmitted on a non-anchor carrier” and the“case where an SIB1-NB is transmitted on both an anchor-carrier and anon-anchor carrier”.

When the remaining SIB-NBs (called SIBx-NBs) other than an SIB1-NB istransmitted on a non-anchor carrier, a subframe section in which a userequipment may expect an NRS may be defined differently from a subframesection when an SIB1-NB is transmitted on a non-anchor carrier.

The reason for this is that in the TDD system, an SIB1-NB is nottransmitted in contiguous subframes, but an SIBx-NB is transmitted in adownlink subframe in which the same TBS is contiguous (valid).

That is, although a valid subframe is contiguously present, an SIB1-NBitself is transmitted in a non-contiguous subframe, but an SIBx-NB iscontiguously transmitted in a valid subframe. Accordingly, an NRS may beexpected within multiple subframes in which the SIBx-NB is transmitted.

Furthermore, an NRS may be additionally expected to be permitted in someN1, N2 (valid) subframes ahead of/behind contiguous subframes in whichan SIBx-NB is transmitted for cross-subframe channel estimation.

This is a purpose similar to that a user equipment always does notexpect an NRS in a valid subframe on a non-anchor carrier and can expectan NRS only in some (valid) subframe sections ahead of/behind a(contiguous) subframe in which an NPDCCH(/NPDSCH) reception is expected.

Message Interpretation and Configuration of SIB1-NB

Fourth, a method of interpreting and configuring the message of anSIB1-NB is described.

In a TDD NB-IoT system, an SIBx-NB may be transmitted in a third carriernot an anchor-carrier.

In this case, the third carrier is a non-anchor carrier or means aspecific carrier or PRB location that is not used by corresponding cellfor NPSS/NSSS/NPBCH transmission, but satisfies an anchor carrier rasteroffset condition.

Furthermore, a TDD system used in this specification is an unpairedsystem or may be interpreted as the same meaning as a system having theframe structure type 2.

A case where an SIBx-NB is transmitted on a third carrier may be dividedas follows. In each case, the message interpretation and configurationof an SIB1-NB and an operation procedure of a user equipment may followdifferent methods.

1. An SIB1-NB is transmitted on an anchor carrier, but the remainingother SIBx-NBs may be transmitted on a third carrier not ananchor-carrier.

2. An SIB1-NB may be transmitted on a third carrier, and the remainingother SIBx-NBs may be transmitted on the same carrier as an SIB1-NB.

3. An SIB1-NB may be transmitted on a third carrier and the remainingother SIBx-NBs may be transmitted on a carrier different from that of anSIB1-NB.

In this case, the SIBx-NB may be permitted to be transmitted on ananchor carrier.

Position information of the carrier of the SIB1-NB and locationinformation of the remaining other SIBx-NB carriers in the above 1. To3. May be included in each MIB-NB and SIB1-NB.

The MIB-NB and the SIB1-NB may not be transmitted using sufficientdownlink resources like the remaining other SIBx-NB. Accordingly, theyare not notified as a channel number of a form, such asARFCN-ValueEUTRA, and the location of the carrier in which the SIB1-NBis transmitted may be defined as a relative PRB location with ananchor-carrier (one of one or more pre-determined offset values).

The location of a carrier in which the remaining SIBx-NBs aretransmitted may be defined as a relative PRB location with ananchor-carrier (one of one or more pre-determined offset values, and therange of the offset value may be the same as or different from the rangeof an offset value for providing notification of an SIB1-NB transmissionlocation) or may be defined as a relative PRB location with a carrier onwhich an SIB1-NB is transmitted.

In this case, when an SIB1-NB is transmitted on both an anchor-carrierand a non-anchor carrier, a relative PRB location with theanchor-carrier may be first notified.

In general, this may be different from the use of a channel number of aform, such as ARFCN-ValueEUTRA, when a non-anchor carrier is configuredin an NB-IoT system.

When an SIB1-NB is transmitted on a third carrier, it may be necessaryto identify whether some of the message of the SIB1-NB is information onan anchor-carrier or information on the third carrier on which theSIB1-NB is transmitted.

That is, some information (type-A) may be interpreted by applying it toan anchor-carrier and the third carrier on which the SIB1-NB istransmitted in common. Some information (type-B) may be interpreted byapplying it to only the third carrier on which the SIB1-NB istransmitted.

If a specific identical parameter of the type-A information is notapplied to an anchor-carrier and a third carrier on which an SIB1-NB istransmitted in common, but is to be separately applied to the thirdcarrier on which an SIB1-NB is transmitted, another correspondingspecific identical parameter may be further included and configured in amessage.

As described above, if another specific identical parameter is furtherpresent in the type-A and is to be defined as a value different fromthat of an anchor-carrier in which a third carrier on which an SIB1-NBis transmitted, a message in which such an operation is permitted iscalled a type-C.

If only one value is allocated to a parameter present in Type-C, likeType-A, this is applied to an anchor-carrier and a third carrier onwhich an SIB1-NB is transmitted in common and interpreted.

If two values are allocated to a parameter present in Type-Cm one valueis applied to an anchor-carrier and the remaining one value is appliedto a third carrier on which an SIB1-NB is transmitted.

Furthermore, when an SIB1-NB schedules the remaining other SIBx-NBs, ifthe SIB1-NB schedules the remaining other SIBx-NBs as a third carrierdifferent from that of the SIB1-NB, a similar issue may occur again.

That is, if an SIB1-NB wants to indicate a specific parameter as aseparate value based on a carrier on which an SIBx-NB is transmitted, itmay be identified as a message of Type-B or Type-C.

That is, in the case of Type-B, a parameter is directly transferred withrespect to the carrier of an SIBx-NB scheduled by an SIB1-NB. In thecase of Type-C, if a parameter is applied to all of an anchor-carrierand a third carrier on which an SIB1-NB is transmitted and a thirdcarrier in which an SIBx-NB will be transmitted in common or values morethan one value are present in a specific parameter, the parameter may beapplied to the anchor-carrier, the third carrier on which an SIB1-NB istransmitted, and the third carrier on which an SIBx-NB is transmitted.

Such a problem does not occur in an FDD NB-IoT system up to Release 15.

The reason for this is that all types of system information arebasically transmitted on an anchor-carrier.

For example, cellSelectionInfo information of an SIB1-NB is informationrelated to the cell selection process of a user equipment.

The information may be a value always defined as the measurement of ananchor-carrier.

However, the information may be cell selection-related information basedon a measurement value of a corresponding third carrier on which anSIB1-NB is transmitted in order to reduce the complexity of a userequipment (power consumption and time delay may also be included in thecomplexity) for frequency re-tuning into an anchor-carrier in order tomeasure radio resource management (RRM) or reference signal receivedpower (RSRP) or reference signal received quality (RSRQ), etc. on thecorresponding third carrier in which the user equipment has detected theSIB1-NB.

For example, downlinkBitmap information may indicate the valid orinvalid of a subframe.

If the information is included in an SIB1-NB, correspondingdownlinkBitmap information may be applied to all of an anchor-carrierand a third carrier on which an SIB1-NB is transmitted in common.

Alternatively, the downlinkBitmap information may be limited to bealways applied to only an anchor-carrier.

Furthermore, if two types of downlinkBitmap information are present, onemay be downlinkBitmap information for an anchor-carrier and the othermay be downlinkBitmap information for a third carrier on which anSIB1-NB is transmitted.

If only one type of downlinkBitmap information is included, it may beassumed that an anchor-carrier and a third carrier on which an SIB1-NBis transmitted use the same downlinkBitmap information.

If an SIB1-NB schedules the remaining other SIBx-NBs in another thirdcarrier, downlinkBitmap information may be applied again similar to theabove case.

That is, if only one type of downlinkBitmap information is presentwithin an SIB1-NB, the corresponding downlinkBitmap information may beapplied to all of an anchor-carrier and a third carrier on which anSIB1-NB is transmitted and a third carrier on which an SIBx-NB istransmitted.

If only two types of downlinkBitmap are present, what each type ofdownlinkBitmap information indicates which carrier may be clearlyincluded.

Alternatively, interpretation may be different depending on the locationof a carrier on which an SIB1-NB is transmitted.

For example, when an SIB1-NB is transmitted on an anchor-carrier and theremaining SIBx-NBs are scheduled as another third carrier, the firstdownlinkBitmap may indicate information on the anchor-carrier and theother downlinkBitmap may indicate subframe information of a carrier onwhich the remaining SIBx-NBs are transmitted.

nrs-CRS-PowerOffset may also be applied in common between ananchor-carrier and a different carrier (carrier on which an SIB1-NB istransmitted and/or an SIBx-NB is transmitted) and interpreted using amethod similar to or identical with the method of the above-describeddownlinkBitmap information.

In this case, information, such as nrs-CRS-PowerOffset, defines only anNRS and CRS power offset always in an anchor-carrier. In the remainingcarriers, NRS power information may use a method of addingnrs-PowerOffsetNonAnchor to an SIB1-NB and independently providingnotification of an NRS power offset between an anchor-carrier and aspecific carrier.

Alternatively, with respect to a third carrier on which an SIB1-NB istransmitted or a third carrier on which the remaining SIBx-NB istransmitted, NRS power-related information may be defined and used asCRS-PowerOffset not nrs-PowerOffsetNonAnchor characteristically, and maybe applied using a method similar to or identical with theabove-described downlinkBitmap information.

The downlinkBitmap information, the nrs-PowerOffsetNonAnchorinformation, etc. may derive downlinkBitmap information, anrs-PowerOffsetNonAnchor degree, etc. of a carrier on which systeminformation is transmitted using a method similar todownlinkBitmapNonAnchor included in CarrierConfigDedicated-NB. That is,downlinkBitmapNonAnchor may be divided into useNoBitmap,useAnchorBitmap, explicitBitmapConfiguration information and may benotified.

In the case of useNoBitmap, all downlink subframes (may include some ofor all the special subframe formats of a special subframe) of acorresponding carrier or an indicated carrier may be interpreted asvalid downlink subframes.

In the case of useAnchorBitmap, valid downlink subframe information of acorresponding carrier or an indicated carrier may be interpreted asbeing the same as a value configured for an anchor-carrier.

explicitBitmapConfiguration may independently indicate valid downlinksubframe information of a corresponding carrier or an indicated carrierdirectly.

A case where eutraControlRegionSize may be omitted when SIB1-NB istransmitted on a non-anchor carrier may be different.

In the case of the in-band operation mode, eutraControlRegionSize istransmitted in an SIB1-NB. If an SIB1-NB is transmitted on a non-anchorcarrier and an anchor-carrier and the non-anchor carrier have differentoperation modes, eutraControlRegionSize may always need to betransmitted.

For example, if an anchor-carrier is an in-band operation mode and anSIB1-NB is transmitted in the non-anchor carrier of a guard-band, theSIB1-NB includes eutraControlRegionSize information, andeutraControlRegionSize may indicate the control region size of theanchor-carrier.

Furthermore, if an anchor-carrier is a guard band operation mode and anSIB1-NB is transmitted on the non-anchor carrier of an in-band, theSIB1-NB includes information of eutraControlRegionSize, andeutraControlRegionSize may be used to indicate the control region sizeof an in-band.

Furthermore, an SIB2-NB may configure a random access-related parameter,which includes information on an NPRACH and an NPDCCH search space forreceiving random access response (RAR).

In the FDD NB-IoT system, NPRACH and NPDCCH search space information fora random access response (RAR) configured as an SIB2-NB is applied toonly an anchor-carrier.

An SIB22-NB is used for a configuration so that random access can beperformed in a non-anchor carrier (a series of processes of transmittingan NPRACH, receiving an RAR to the transmission, and then completingrandom access).

Furthermore, whether random access can be performed in a non-anchorcarrier up to Release 14 is dependent on the capability of a userequipment.

Likewise, in the TDD NB-IoT system, whether random access can beperformed in a non-anchor carrier is assumed to be the capability of auser equipment.

If the corresponding capability means only whether an NPRACH can betransmitted on a non-anchor carrier, an NPRACH parameter configured asan SIB2-NB may be interpreted as an anchor-carrier.

In this case, if an SIB1-NB and/or the remaining SIBx-NB have not beentransmitted on an anchor carrier or a downlink subframe for RARtransmission is not sufficient in order to transmit system information,an NPDCCH search space for an RAR configured as an SIB2-NB may need tobe configured as a third carrier not an anchor-carrier.

In a conventional technology, Msg.1 (NPRACH) transmission and Msg.3transmission use the same carrier-A, and Msg.2 (RAR) reception and Msg.4reception use the same carrier-B.

In this case, the carrier-A and the carrier-B may not be a 1-to-1 pair.

In this case, the carrier-A and the carrier-B could not be configured asa combination of an anchor-carrier and a non-anchor carrier.

In contrast, in the TDD NB-IoT system, an Msg.1 transmission carrierconfigured as an SIB2-NB as described above may be interpreted as ananchor-carrier, and a carrier in which Msg.2 is expected may beconfigured as a non-anchor carrier.

In this case, if a non-anchor carrier in which Msg.2 is expected isnecessary, such non-anchor carrier information may need to beadditionally included in Msg.2 information.

If non-anchor carrier information is not present, a user equipment mayinterpret that Msg.2 is expected in a carrier (i.e., an anchor-carrierin the example) corresponding to an Msg.1 carrier.

Furthermore, the Msg.1 transmission of a random access-related parameterconfigured in an SIB2-NB may be indicated as a specific non-anchorcarrier.

In such a case, a TDD system may be applied only when the Msg.1transmission of a user equipment is always possible in a non-anchorcarrier.

Furthermore, the random access-related parameter configured in theSIB2-NB may include all of an anchor-carrier and a carrier on which anSIB1-NB has been transmitted and/or a carrier on which the SIB2-NB hasbeen transmitted, and may be applied (a random access-related parameterfor one carrier may be extended as a carrier unit or an independentrandom access-related parameter for each required carrier may beadditionally configured/included).

In such a case, if both the SIB1-NB and the SIB2-NB are transmitted onan anchor carrier, this may be similar to the existing method in whichan SIB2-NB configures random access only on an anchor carrier.

That is, system information may interpret that Msg.1 has been naturallyconfigured in an anchor-carrier with respect to the anchor-carrier.

In such a case, Msg.2 may be indicated as a specific non-anchor carrier.

The reason for this is that most of downlink subframes may have beenused in order to transmit the system information.

If one or more pieces of system information are not transmitted on ananchor-carrier, an SIB2-NB may be considered to have configured a randomaccess-related parameter with respect to one or more carriers includingan anchor-carrier.

In this case, a user equipment not supporting NPRACH transmission for anon-anchor carrier may limitedly interpret or first select the NPRACHtransmission carrier of the SIB2-NB as an anchor-carrier only.

In contrast, even in such a case (not transmitting an NPRACH on anon-anchor carrier), Msg.2 may be configured to be received on anon-anchor carrier.

A user equipment capable of transmitting an NPRACH on a non-anchorcarrier may interpret random access-related information configured in anSIB2-NB with respect to both an anchor-carrier and a non-anchor carrier.

Furthermore, a method of actually selecting an Msg.1 transmissioncarrier may operate like a method of selecting a specific probability (amethod of stochastically selecting a carrier on which Msg.1 will betransmitted among an anchor-carrier and one or more non-anchor carriersin the existing SIB22-NB) as a method similar to the method ofnon-anchor NPRACH transmission of Rel.14.

If an anchor-carrier on which an NPSS, NSSS, NPBCH is transmitted is theguardband operation mode and an SIB1-NB is transmitted in a non-anchorof an inband same or different PCI mode, an MIB-NB may need to provideadditional information on a non-anchor carrier on which an SIB1-NB istransmitted.

For example, if a non-anchor carrier on which an SIB1-NB is transmittedis the inband same PCI mode, eutra-CRS-SequenceInfo may be necessary.

Alternatively, in the case of the inband different PCI mode,eutra-NumCRS-Ports (or additionally rasterOffset) information may beadditionally necessary.

Alternatively, such a parameter may be limited to a specific value(e.g., eutra-NumCRS-Ports may always be limited to the same value as ananchor-carrier and or 2 or 4).

An additional method of indicating the operation mode of a non-anchorcarrier on which an SIB1-NB is transmitted may be necessary.

To this end, spare 3 bits of a Guardband-NB may be used.

For example, some state(s) of 8 states represented in 3 bits mayindicate an operation mode when an SIB1-NB needs to be transmitted on anon-anchor carrier.

Furthermore, other some state(s) may represent the number of CRS antennaports when a non-anchor carrier on which an SIB1-NB is transmitted isthe in-band different PCI mode.

If a carrier on which an SIB1-NB is transmitted is represented as 2 bitsin an MIB-NB, the A-state of 4 states (A, B, C, D) may mean that theSIB1-NB is transmitted on an anchor-carrier. The B-state of the 4 statesmay mean that the SIB1-NB is transmitted on a non-anchor carrier havingan offset of X (e.g., 1PRB) with respect to an anchor-carrier. TheC-state of the 4 states may mean that the SIB1-NB is transmitted on anon-anchor carrier having an offset of Y (e.g., −X) with respect to ananchor-carrier. The D-state of the 4 states may mean that the operationmode of a non-anchor carrier on which the SIB1-NB is transmitted isdifferent from the operation mode of an anchor-carrier.

In this case, D does not include a case where “an anchor-carrier is theinband same PCI mode and a non-anchor is the inband different PCI mode”or an opposite case.

In this case, the “anchor-carrier may indicate an inband same PCI modeand the non-anchor may indicate a guardband mode” or the “anchor-carriermay indicate an inband different PCI mode and the non-anchor mayindicate a guardband mode” or the “anchor-carrier may indicate aguardband mode and the non-anchor may indicate an inband same PCIguardband mode” or the “anchor-carrier may indicate a guardband mode andthe non-anchor may indicate an inband same PCI guardband mode.”

In this case, if an anchor-carrier is a guardband mode, there is aproblem in whether a non-anchor carrier on which an SIB1-NB istransmitted is an inband same PCI mode or an inband different PCI modecannot be represented.

One state or bit of the spare 3 bits of a Guardband-NB may be used as amethod of solving this problem.

Furthermore, the remaining 7 states or 2 bits may be used to representbandwidth information of a system.

Accordingly, if an NB-IoT user equipment can be aware of a systembandwidth, an accurate PRB location where an SIB1-NB is transmittedwithin an inband may be fixed to a specific location (e.g., a PRBclosest to an anchor-carrier from the center of a system band).

If an anchor-carrier has an operation mode of an in-band same ordifferent PCI operation mode and an SIB1-NB is transmitted in aguard-band, a user equipment receives the SIB1-NB by interpreting acarrier format indicator (CFI) as a guard-band mode.

That is, the user equipment may assume a CFI different from an operationmode indicated in an MIB-NB, and may receive the SIB1-NB.

For example, if an operation mode is an inband mode, a CFI that may beassumed by a user equipment prior to SIB1-NB detection is 3. If acarrier on which an SIB1-NB is transmitted is a guard-band (or if thecarrier does not include an in-band), a CFI may be interpreted as “0”with respect to the carrier on which the SIB1-NB is transmitted.

An actual CFI of an anchor-carrier on which an MIB-NB is transmittedassumes a CFI notified in an SIB1-NB.

The transport block size (TBS) of an SIB1-NB may be differentlyinterpreted depending on the operation mode of a carrier on which anSIB1-NB is transmitted.

That is, the SIB1-NB TBS is provided in an MIB-NB, but may bedifferently interpreted when an SIB1-NB is transmitted on a non-anchorcarrier.

Furthermore, an SIB1-NB TBS indicated in an MIB-NB may be differentlyinterpreted depending on the operation mode of a non-anchor carrier onwhich an SIB1-NB is transmitted.

In this case, “for each operation mode” includes the operation mode ofan anchor-carrier and the operation mode of a non-anchor carrier onwhich an SIB1-NB is actually transmitted.

For example, when an anchor carrier is an in-band operation mode, but anSIB1-NB is transmitted on the same carrier, an SIB1-NB TBS isinterpreted as a value indicated in an MIB-NB.

However, when an SIB1-NB is transmitted on a non-anchor carrier and thecorresponding non-anchor carrier is an in-band operation mode, anSIB1-NB TBS may be interpreted as a value twice greater than a valueindicated in an MIB-NB.

When an SIB1-NB is transmitted on a non-anchor carrier and thecorresponding non-anchor carrier is a guard band operation mode, anSIB1-NB TBS may be interpreted as a value four times greater than avalue indicated in an MIB-NB.

When an SIB1-NB is transmitted on a non-anchor carrier, downlinkBitmapand nrs-CRS-PowerOffset transmitted in the SIB1-NB may be differentlyinterpreted or differently applied or an additional parameter may needto be defined depending on a combination (pair) of an anchor-carrier andthe non-anchor carrier on which the SIB1-NB is transmitted.

1. When a non-anchor carrier on which an SIB1-NB is transmitted is aguard band operation mode or a standalone operation mode, downlinkBitmapis applied to both an anchor-carrier and the corresponding non-anchorcarrier.

2. When a non-anchor carrier on which an SIB1-NB is transmitted is anin-band operation mode,

A. If an Anchor-Carrier is an in-Band Operation Mode,

{circle around (1)} downlinkBitmap is applied to both the anchor-carrierand the corresponding non-anchor carrier.

{circle around (2)} nrs-CRS-PowerOffset is applied to the anchor carrier(or the corresponding non-anchor carrier).

{circle around (3)} “NRS power offset (between NRS and E-UTRA CRS)”information of the non-anchor carrier may be defined as a fixed value(may be different depending on an anchor carrier operation mode) or maybe applied to the corresponding non-anchor carrier (or anchor-carrier)based on an additional other parameter.

In this case, the “NRS power offset” may be defined identically orsimilarly to nrs-CRS-PowerOffset or a relative power ratio may bedefined between the NRSs of a corresponding non-anchor carrier (oranchor-carrier) of an anchor carrier (or corresponding non-anchorcarrier).

B. If an Anchor-Carrier is a Guard Band Operation Mode,

{circle around (1)} nrs-CRS-PowerOffset is applied to all ofcorresponding non-anchor carriers.

{circle around (2)} downlinkBitmap is applied to the anchor carrier (ora corresponding non-anchor carrier).

In this case, a downlinkBitmap length may be permitted to be configuredup to a maximum length in the inband operation mode.

In such a case, characteristically, in the guard band operation mode,downlinkBitmap information having the same period as the downlinkBitmaplength may be applied to an anchor-carrier.

That is, downlinkBitmap may be applied to an anchor-carrier and anon-anchor carrier on which an SIB1-NB is transmitted as the same periodand the same value.

“NB-IoT subframe (e.g., a subframe(s) indicated to be available in anNB-IoT in downlinkBitmap)” information of a non-anchor carrier may bedefined as a fixed value (may be different depending on an anchorcarrier operation mode) or may be applied to a corresponding non-anchorcarrier (or anchor-carrier) by an additional other parameter.

In this case, the “NB-IoT subframe” may be defined identically withdownlinkBitmap (or a format or the length of a bit map) or the length ofa bitmap may be differently defined to indicate only a downlink subframe(or with respect to only a downlink and special subframe).

The reason for this is that since a purpose for declaring an UL invalidsubframe as downlinkBitmap is enhanced interference mitigation andtraffic adaptation (eIMTA) of an LTE system, if an UL subframe has apossibility that it may change into a DL subframe, an NB-IoT (or eMTC)system is prevented from using a corresponding subframe as an ULsubframe, but such a characteristic is not different for each carrier inthe same subframe.

When all the MIB-NB, SIB1-NB and SIB2-NB are not transmitted on ananchor carrier, nrs-Power transmitted in the SIB2-NB is differentlyinterpreted or differently applied as follows depending on a combination(pair) of carriers used to transmit the MIB-NB and the SIB1-NB and theSIB2-NB or an additional parameter needs to be defined.

nrs-Power may mean the “downlink narrowband reference-signal EPRE” of ananchor-carrier regardless of the location of a carrier on which anSIB2-NB is transmitted (whether it is an anchor carrier, a carrierdifferent from that of an SIB1-NB, etc.).

In this case, nrs-PowerOffsetNonAnchor information on a carrier on whichan SIB2-NB is transmitted may also be included so that the NRSRPmeasurement value of the carrier on which the SIB2-NB is transmitted canbe used to select CE levels (4 CE levels are present).

This is for minimizing an operation of moving, by a user equipment,NRSRP measurement used for CE level selection to an anchor-carrier againafter the user equipment receives an SIB2-NB.

Of course, for the same purpose, nrs-Power means a “downlink narrowbandreference-signal EPRE” at the location of a carrier on which the SIB2-NBis transmitted. Information on NRS power of an anchor-carrier may betransmitted through nrs-PowerOffsetNonAnchor.

If NRSRP measurement for CE level selection is based on a carrier onwhich an SIB2-NB is transmitted, nrs-Power included in the SIB2-NB maybe “downlink narrowband reference-signal EPRE” information of thecarrier on which the SIB2-NB is transmitted.

That is, the nrs-Power information may be “downlink narrowbandreference-signal EPRE” information of an anchor-carrier or “downlinknarrowband reference-signal EPRE” information of a non-anchor carrierdepending on the carrier on which the SIB2-NB is transmitted.

The method has a difference in that unlike in FDD, a carrier used for CElevel selection in the TDD NB-IoT system is a carrier on which anSIB2-NB is transmitted or uses both an anchor-carrier and a carrier onwhich an SIB2-NB is transmitted.

That is, a CE level may be selected based on an NRS transmitted on ananchor carrier depending on the location of a carrier on which anSIB2-NB is transmitted, or a CE level may be selected based on the NRSof a non-anchor carrier (on which an SIB2-NB is transmitted).

Operation Related to an RRM or CE Level Selection when SystemInformation is Transmitted on Non-Anchor Carrier

Fifth, an operation related to the RRM or CE level selection, etc. of auser equipment when system information is transmitted on a non-anchorcarrier is described.

A user equipment needs to select a CE level before it performs a randomaccess procedure.

This may be selected by comparing a measured value of RSRP with a valueof rsrp-ThresholdsPrachInfoList in a random access-related parameterusing an NRS (NSSS may be additionally used, but this may be differentdepending on whether a user equipment can be aware of a parameterrelated to the power offset relation of the NRS and the NSSS, etc. at acorresponding point of time).

In this case, in general, the RSRP measurement value using the NRS ispossible only in an anchor-carrier.

However, when system information is not transmitted on ananchor-carrier, RSRP measurement may be performed in a carrier in whichspecific system information has been received.

That is, a user equipment may receive system information in a carriernot an anchor-carrier, and may not perform frequency re-tuning in ananchor-carrier for CE level selection or NPRACH power control.

In this case, system information may be an SIB1-NB or system information(e.g., may be an SIB2-NB or an SIB22-NB) that configures randomaccess-related information.

Furthermore, if system information transmits Msg.1 on an anchor carrieralthough it is received on a non-anchor carrier, RSRP measurement for CElevel selection and RRM may need to be performed on the anchor carrier.

DL/UL Non-Anchor Carrier Configuration

Sixth, the configuration of a DL/UL non-anchor carrier is described.

A frequency division duplex (FDD) system may configure DL and UL asrespective non-anchor carriers.

However, in TDD, when a non-anchor carrier may be configured, DL and ULmay be configured without a distinction.

That is, in TDD, both DL and UL may be configured in a correspondingcarrier as one non-anchor carrier configuration because DL and UL arepresent as a TDM scheme in one carrier.

However, if a non-anchor carrier is configured in a PRB location (LTEinband center 6RB) where a PSS/SSS is transmitted, only NB-IoT UL needsto be performed in the corresponding non-anchor carrier.

The reason for this is that an NB-IoT DL carrier configuration is notpermitted in center 6RBs in which a PSS and NSS, MIB are transmitted inFDD NB-IoT.

Accordingly, a user equipment receives a configuration for a non-anchor.If the location of the corresponding carrier overlaps center 6 RBs, theuser equipment may be limited to expect only UL on the correspondingcarrier.

The Number of NRS and CRS Ports for a Non-Anchor Carrier SIB1-NB

Seventh, when an SIB1-NB is transmitted on a non-anchor carrier, thenumbers of NRS and CRS ports is described.

If an anchor carrier is a guard band operation mode and a non-anchorcarrier on which an SIB1-NB is transmitted is an in-band operation mode,a user equipment requires NRS port number and CRS port numberinformation for SIB1-NB decoding.

This may be differently defined or assumed depending on whether thein-band operation mode is same-PCI or different-PCI.

1) If a Non-Anchor Carrier on which an SIB1-NB is Transmitted is anin-Band Same PCI Mode

The numbers of NRS and CRS ports of the corresponding non-anchor carrierare the same as the number of NRS ports of an anchor-carrier.

The reason for this is that the numbers of NRS and CRS ports have beenassumed to be the same in the case of an in-band same PCI mode in theexisting FDD NB-IoT. In TDD, the same method may be applied.

2) If a Non-Anchor Carrier on which an SIB1-NB is Transmitted is anin-Band Different PCI Mode

The number of NRS ports of the corresponding non-anchor carrier is thesame as the number of NRS ports of an anchor-carrier. The number of CRSports of the corresponding non-anchor carrier may be assumed to be 4.

That is, a user equipment assumes the number of CRS ports of acorresponding non-anchor carrier to be 4 before SIB1-NB decoding iscompleted, and attempts SIB1-NB decoding to which rate matching orpuncturing has been applied.

Of course, if the design of a user equipment similar to that of FDD isconsidered, rate matching may be said to be more appropriate.

Furthermore, when the number of CRS ports of a corresponding carrier isexplicitly transmitted in an SIB1-NB, a user equipment may assume thenumber of CRS ports different from SIB1-NB decoding with respect to therate matching of a corresponding carrier after SIB1-NB decoding.

The above-described contents corresponding to the first to the seventhmay be independently applied or one or more combination of them may beapplied or may be combined and applied in order to perform a method oftransmitting an SIB1-NB, which is proposed in this specification.

User equipment and base station operations for transmitting (orreceiving) an SIB1-NB, which are proposed in this specification, basedon the above-described contents are described.

FIG. 16 is a flowchart showing an example of a user equipment operationfor performing a method proposed in this specification.

That is, FIG. 16 shows a method of receiving system information in awireless communication system supporting a time division duplex (TDD)narrowband (NB).

First, a user equipment receives, from a base station, first systeminformation on an anchor carrier (S1610).

The first system information includes first information, indicatingwhether a carrier used for second system information is an anchorcarrier or a non-anchor carrier, and the second information on thelocation of the non-anchor carrier used for the second systeminformation.

The first information is configured as the non-anchor carrier.

Furthermore, the user equipment receives, from the base station, thesecond system information on the non-anchor carrier based on the firstsystem information (S1620).

The second system information may be received in a subframe #0 and asubframe #5. The repetition number of the second system information onthe non-anchor carrier may be 8 or 16.

In this case, the repetition number may be determined based on aspecific parameter included in the first system information.

Furthermore, the user equipment may expect or assume that a narrowbandreference signal (NRS) is received from the base station in the subframe#0 and the subframe #5.

In this case, the first system information may be amasterinformationblock (MIB)-narrowband (NB), and the second systeminformation may be a systeminformationblock1 (SIB1)-NB.

Furthermore, the first system information may further include operationmode information indicating then operation mode of the system.

In this case, the location of the non-anchor carrier used for the secondsystem information may be determined based on the operation mode.

In this case, the location of the non-anchor carrier may be determinedas a relative location with the anchor carrier.

The relative location may be represented as the interval of a physicalresource block (PRB).

If the operation mode has been configured as a guard band, the secondcontrol information may indicate a carrier on the same side as theanchor carrier or a carrier on the side opposite to the anchor carrier.

Alternatively, when the operation mode is an in-band or standalone, thesecond information may indicate a frequency value lower than or higherthan the anchor carrier.

Furthermore, the first system information may further include thirdinformation indicating that the number of cell-specific reference signal(CRS) ports of the non-anchor carrier is the same as the number of NRSports of the anchor carrier or is 4.

In this case, the operation mode of the non-anchor carrier may be anin-band-different PCI.

The reason why an SIB1-NB proposed in this specification has to betransmitted on a non-anchor carrier is described below.

Unlike in the LTE system, in an NB-IoT system characterized by coverageenhancement, all channels and signals basically occupy a minimum 1subframe section.

Accordingly, the NB-IoT system requires 3 subframes for only NPSS, NSSSand NPBCH transmission.

However, since the NPSS, NSSS and NPBCH transmission period is everymsec or 20 msec, the number of subframes used for NPSS, NSSS and NPBCHtransmission within each 20 msec is 5.

Furthermore, in the case of an UL/DL configuration supported in a TDDNB-IoT system, a subframe that may be assumed to be always DL in allUL/DL configurations (subframe that may be assumed to be downlink in allUL/DL configurations may be used for SIB1-NB transmission because a TDDconfiguration is notified in an SIB1-NB) includes only a No. 0 subframeof an odd-numbered radio frame.

Furthermore, an SIB1-NB requires many repetition transmissions when aTBS is great because the SIB1-NB can support various transport blocksizes (TBSs).

In this case, it may be difficult to solve interference between neighborcells through TDD due to the repetition transmissions.

Accordingly, in order to solve such a problem, an SIB1-NB needs to betransmitted on a non-anchor carrier on an anchor-carrier.

A difference between a transmission method through the non-anchorcarrier of an SIB1-NB proposed in this specification and the carrieraggregation (CA) method of the existing LTE system is that in the methodproposed in this specification, basic broadcast information is limitedto a specific component carrier (CC) and not transmitted.

In the CA of the LTE system, a given CC may become a primary-cell(P-cell) for each user equipment. In contrast, in the NB-IoT system, ifmultiple NB-IoT carriers are present, only one anchor-carrier isdefined.

Accordingly, the SIB1-NB transmission method proposed in thisspecification is different from the CA of the LTE system in that (basic)broadcast information is transmitted on a different carrier.

A part in which the method proposed in this specification is implementedin a user equipment is described with reference to FIGS. 16, 18 and 19.

In a wireless communication system supporting a time division duplex(TDD) narrowband (NB), in order to receive system information, a userequipment includes a radio frequency (RF) module for transmitting andreceiving radio signals and a processor controlling the RF module.

The processor of the user equipment controls the RF module to receivefirst system information from a base station on an anchor carrier.

The first system information includes first information, indicatingwhether a carrier used for second system information is an anchorcarrier or a non-anchor carrier, and second information on the locationof the non-anchor carrier used for the second system information.

The first information is configured as the non-anchor carrier.

Furthermore, the user equipment controls the RF module to receive thesecond system information from the base station on the non-anchorcarrier based on the first system information.

The second system information may be received in a subframe #0 and asubframe #5. The repetition number of the second system information onthe non-anchor carrier may be 8 or 16.

In this case, the repetition number may be determined based on aspecific parameter included in the first system information.

Furthermore, the user equipment may expect or assume that a narrowbandreference signal (NRS) is received from the base station in the subframe#0 and the subframe #5.

In this case, the first system information may be amasterinformationblock (MIB)-narrowband (NB), and the second systeminformation may be a systeminformationblock1 (SIB1)-NB.

Furthermore, the first system information may further include operationmode information indicating the operation mode of the system.

In this case, the location of the non-anchor carrier used for the secondsystem information may be determined based on the operation mode.

In this case, the location of the non-anchor carrier may be determinedas a relative location with the anchor carrier.

The relative location may be represented as the interval of a physicalresource block (PRB).

If the operation mode has been configured as a guard band, the secondcontrol information may indicate a carrier on the same side as theanchor carrier or a carrier on the side opposite to the anchor carrier.

Alternatively, when the operation mode is an in-band or standalone, thesecond information may indicate a frequency value lower than or higherthan the anchor carrier.

Furthermore, the first system information may further include thirdinformation indicating that the number of cell-specific reference signal(CRS) ports of the non-anchor carrier is the same as the number of NRSports of the anchor carrier or is 4.

In this case, the operation mode of the non-anchor carrier may be anin-band-different PCI.

FIG. 17 is a flowchart showing an example of a base station operationfor performing a method proposed in this specification.

That is, FIG. 17 shows a method of transmitting system information in awireless communication system supporting a time division duplex (TDD)narrowband (NB).

First, a base station transmits first system information to a userequipment on an anchor carrier (S1710).

The first system information includes first information indicatingwhether a carrier used for second system information is an anchorcarrier or a non-anchor carrier and second information on the locationof the non-anchor carrier used for the second system information.

The first information is configured as the non-anchor carrier.

Furthermore, the base station transmits the second system information tothe user equipment on the non-anchor carrier based on the first systeminformation (S1720).

The second system information may be received in a subframe #0 and asubframe #5. The repetition number of the second system information onthe non-anchor carrier may be 8 or 16.

In this case, the repetition number may be determined based on aspecific parameter included in the first system information.

Furthermore, the base station may transmit a narrowband reference signal(NRS) to the user equipment in the subframe #0 and the subframe #5.

In this case, the first system information may be amasterinformationblock (MIB)-narrowband (NB), and the second systeminformation may be a systeminformationblock1 (SIB1)-NB.

Furthermore, the first system information may further include operationmode information indicating the operation mode of the system.

In this case, the location of the non-anchor carrier used for the secondsystem information may be determined based on the operation mode.

In this case, the location of the non-anchor carrier may be determinedas a relative location with the anchor carrier.

The relative location may be represented as the interval of a physicalresource block (PRB).

If the operation mode has been configured as a guard band, the secondcontrol information may indicate a carrier on the same side as theanchor carrier or a carrier on the side opposite to the anchor carrier.

Alternatively, when the operation mode is an in-band or standalone, thesecond information may indicate a frequency value lower than or higherthan the anchor carrier.

Furthermore, the first system information may further include thirdinformation indicating whether the number of cell-specific referencesignal (CRS) ports of the non-anchor carrier is the same as the numberof NRS ports of the anchor carrier or is 4.

In this case, the operation mode of the non-anchor carrier may be anin-band-different PCI.

A part in which the method proposed in this specification is implementedin the base station is described with reference to FIGS. 17 to 19.

In a wireless communication system supporting a time division duplex(TDD) narrowband (NB), in order to transmit system information, the basestation includes a radio frequency (RF) module for transmitting andreceiving radio signals and a processor controlling the RF module.

The processor of the base station controls the RF module to transmitfirst system information to a user equipment on an anchor carrier.

The first system information includes first information indicatingwhether a carrier used for second system information is an anchorcarrier or a non-anchor carrier and second information on the locationof the non-anchor carrier used for the second system information.

The first information is configured as the non-anchor carrier.

Furthermore, the base station controls the RF module to transmit thesecond system information to the user equipment on the non-anchorcarrier based on the first system information.

The second system information may be received in a subframe #0 and asubframe #5, and the repetition number of the second system informationon the non-anchor carrier may be 8 or 16.

In this case, the repetition number may be determined based on aspecific parameter included in the first system information.

Furthermore, the base station may transmit a narrowband reference signal(NRS) to the user equipment in the subframe #0 and the subframe #5.

In this case, the first system information may be amasterinformationblock (MIB)-narrowband (NB), and the second systeminformation may be a systeminformationblock1 (SIB1)-NB.

Furthermore, the first system information may further include operationmode information indicating the operation mode of the system.

In this case, the location of the non-anchor carrier used for the secondsystem information may be determined based on the operation mode.

In this case, the location of the non-anchor carrier may be determinedas a relative location with the anchor carrier.

The relative location may be represented as the interval of a physicalresource block (PRB).

If the operation mode has been configured as a guard band, the secondcontrol information may indicate a carrier on the same side as theanchor carrier or a carrier on the side opposite to the anchor carrier.

Alternatively, if the operation mode is an in-band or standalone, thesecond information may indicate a frequency value lower than or higherthan the anchor carrier.

Furthermore, the first system information may further include thirdinformation indicating whether the number of cell-specific referencesignal (CRS) ports of the non-anchor carrier is the same as the numberof NRS ports of the anchor carrier or is 4.

In this case, the operation mode of the non-anchor carrier may be anin-band-different PCI.

General Apparatus to which the Present Invention May be Applied

FIG. 18 illustrates a block diagram of a wireless communicationapparatus to which methods proposed in this specification may beapplied.

Referring to FIG. 18, the wireless communication system includes an eNB1810 and multiple user equipments 1820 disposed within the eNB region.

The eNB and the user equipment may be represented as respective wirelessdevices.

The eNB includes a processor 1811, memory 1812 and a radio frequency(RF) module 1813. The processor 1611 implements the processes and/ormethods proposed in FIGS. 1 to 17. The layers of a radio interfaceprotocol may be implemented by the processor. The memory is connected tothe processor and stores various types of information for driving theprocessor. The RF module is connected to the processor and transmitsand/or receives a radio signal.

The user equipment includes a processor 1821, memory 1822 and an RFmodule 1823.

The processor implements the processes and/or methods proposed in FIGS.1 to 17. The layers of a radio interface protocol may be implemented bythe processor. The memory is connected to the processor and storesvarious types of information for driving the processor. The RF module isconnected to the processor and transmits and/or receives a radio signal.

The memory 1812, 1822 may be positioned inside or outside the processor1811, 1821 and may be connected to the processor by various well-knownmeans.

Furthermore, the eNB and/or the user equipment may have a single antennaor multiple antennas.

An antenna 1814, 1824 functions to transmit and receive radio signals.

FIG. 19 is another example of a block diagram of a wirelesscommunication apparatus to which methods proposed in this specificationmay be applied.

Referring to FIG. 19, the wireless communication system includes a basestation 1910 and multiple user equipments 1920 disposed within the basestation region. The base station may be represented as a transmissiondevice, and the user equipment may be represented as a reception device,and vice versa. The base station and the user equipment includeprocessors 1911 and 1921, memory 1914 and 1924, one or more Tx/Rx radiofrequency (RF) modules 1915 and 1925, Tx processors 1912 and 1922, Rxprocessors 1913 and 1923, and antennas 1916 and 1926, respectively. Theprocessor implements the above-described functions, processes and/ormethods. More specifically, in DL (communication from the base stationto the user equipment), a higher layer packet from a core network isprovided to the processor 1911. The processor implements the function ofthe L2 layer. In DL, the processor provides the user equipment 1920 withmultiplexing between a logical channel and a transport channel and radioresource allocation, and is responsible for signaling toward the userequipment. The transmission (TX) processor 1912 implements varioussignal processing functions for the L1 layer (i.e., physical layer). Thesignal processing function facilitates forward error correction (FEC) inthe user equipment, and includes coding and interleaving. A coded andmodulated symbol is split into parallel streams. Each stream is mappedto an OFDM subcarrier and multiplexed with a reference signal (RS) inthe time and/or frequency domain. The streams are combined using inversefast Fourier transform (iFFT) to generate a physical channel thatcarries a time domain OFDMA symbol stream. The OFDM stream is spatiallyprecoded in order to generate multiple space streams. Each space streammay be provided to a different antenna 1916 through an individual Tx/Rxmodule (or transmitter and receiver 1915). Each Tx/Rx module maymodulate an RF carrier into each space stream for transmission. In theuser equipment, each Tx/Rx module (or transmitter and receiver 1925)receives a signal through each antenna 1926 of each Tx/Rx module. EachTx/Rx module restores information modulated in an RF carrier andprovides it to the RX processor 1923. The RX processor implementsvarious signal processing functions of the layer 1. The RX processor mayperform space processing on information in order to restore a givenspace stream toward the user equipment. If multiple space streams aredirected toward the user equipment, they may be combined into a singleOFDMA symbol stream by multiple RX processors. The RX processor convertsthe OFDMA symbol stream from the time domain to the frequency domainusing fast Fourier transform (FFT). The frequency domain signal includesan individual OFDMA symbol stream for each subcarrier of an OFDM signal.Symbols on each subcarrier and a reference signal are restored anddemodulated by determining signal deployment points having the bestpossibility, which have been transmitted by the base station. Such softdecisions may be based on channel estimation values. The soft decisionsare decoded and deinterleaved in order to restore data and a controlsignal originally transmitted by the base station on a physical channel.A corresponding data and control signal are provided to the processor1921.

UL (communication from the user equipment to the base station) isprocessed by the base station 1910 in a manner similar to that describedin relation to the receiver function in the user equipment 1920. EachTx/Rx module 1925 receives a signal through each antenna 1926. EachTx/Rx module provides an RF carrier and information to the RX processor1923. The processor 1921 may be related to the memory 1924 storing aprogram code and data. The memory may be referred to as acomputer-readable medium.

In the aforementioned embodiments, the elements and characteristics ofthe present invention have been combined in specific forms. Each of theelements or characteristics may be considered to be optional unlessotherwise described explicitly. Each of the elements or characteristicsmay be implemented in a form to be not combined with other elements orcharacteristics. Furthermore, some of the elements and/or thecharacteristics may be combined to form an embodiment of the presentinvention. The sequence of the operations described in the embodimentsof the present invention may be changed. Some of the elements orcharacteristics of an embodiment may be included in another embodimentor may be replaced with corresponding elements or characteristics ofanother embodiment. It is evident that an embodiment may be constructedby combining claims not having an explicit citation relation in theclaims or may be included as a new claim by amendments after filing anapplication.

The embodiment according to the present invention may be implemented byvarious means, for example, hardware, firmware, software or acombination of them. In the case of an implementation by hardware, theembodiment of the present invention may be implemented using one or moreapplication-specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, microcontrollers, microprocessors,etc.

In the case of an implementation by firmware or software, the embodimentof the present invention may be implemented in the form of a module,procedure or function for performing the aforementioned functions oroperations. Software code may be stored in the memory and driven by theprocessor. The memory may be located inside or outside the processor andmay exchange data with the processor through a variety of known means.

It is evident to those skilled in the art that the present invention maybe materialized in other specific forms without departing from theessential characteristics of the present invention. Accordingly, thedetailed description should not be construed as being limitative fromall aspects, but should be construed as being illustrative. The scope ofthe present invention should be determined by reasonable analysis of theattached claims, and all changes within the equivalent range of thepresent invention are included in the scope of the present invention.

INDUSTRIAL APPLICABILITY

The present invention has been described based on an example in which itis applied to the 3GPP LTE/LTE-A system, but may be applied to variouswireless communication systems in addition to the 3GPP LTE/LTE-A system.

1. A method of receiving system information in a wireless communicationsystem supporting a time division duplex (TDD) narrowband (NB), themethod performed by a user equipment comprising: receiving, from a basestation, first system information via an anchor carrier, wherein thefirst system information comprises first information indicating whethera carrier used for second system information is an anchor carrier or anon-anchor carrier and second information on a location of thenon-anchor carrier used for the second system information; receiving,from the base station, the second system information on the non-anchorcarrier based on the first system information.
 2. The method of claim 1,wherein the first system information is a masterinformationblock(MIB)-narrowband (NB), and wherein the second system information is asysteminformationblock1 (SIB1)-NB.
 3. The method of claim 1, wherein thefirst information is configured as the non-anchor carrier.
 4. The methodof claim 3, wherein the first system information further comprisesoperation mode information indicating an operation mode of the system,and wherein the location of the non-anchor carrier used for the secondsystem information is determined based on the operation mode.
 5. Themethod of claim 4, wherein the location of the non-anchor carrier isdetermined as a relative location with the anchor carrier.
 6. The methodof claim 4, wherein when the operation mode is configured as a guardband, the second control information indicates a carrier on a sideidentical with a side of the anchor carrier or a carrier on a sideopposite to the anchor carrier.
 7. The method of claim 4, wherein if theoperation mode is an in-band or standalone, the second informationindicates a frequency value lower than or higher than the anchorcarrier.
 8. The method of claim 5, wherein the relative location isrepresented as an interval of a physical resource block (PRB).
 9. Themethod of claim 1, wherein the first system information furthercomprises third information indicating that a number of cell-specificreference signal (CRS) ports of the non-anchor carrier is identical witha number of NRS ports of the anchor carrier or
 4. 10. The method ofclaim 9, wherein the operation mode of the non-anchor carrier is anin-band-different PCI.
 11. The method of claim 1, wherein the secondsystem information is received in a subframe #0 and a subframe #5. 12.The method of claim 11, wherein a repetition number of the second systeminformation on the non-anchor carrier is 8 or
 16. 13. The method ofclaim 12, wherein the repetition number is determined based on aspecific parameter included in the first system information.
 14. Themethod of claim 11, wherein a narrowband reference signal (NRS) isreceived from the base station in the subframe #0 and the subframe #5.15. A user equipment receiving system information in a wirelesscommunication system supporting a time division duplex (TDD) narrowband(NB), the user equipment comprising: a radio frequency (RF) module fortransmitting and receiving radio signals; and a processor controllingthe RF module, wherein the processor is configured to: receive, from abase station, first system information via an anchor carrier, whereinthe first system information comprises first information indicatingwhether a carrier used for second system information is an anchorcarrier or a non-anchor carrier and second information on a location ofthe non-anchor carrier used for the second system information; receive,from the base station, the second system information on the non-anchorcarrier based on the first system information.
 16. (canceled)